Honestly, it doesn't matter. Breed is often a matter of personal preference more than anything else when it comes to Adventurers. As a versitile profession, both our nanoskills and base skills can and will be important throughout the life of your character. Solitus is typically the default profession, due to well-rounded attributes. Opifex is generally a good profession for Pistol wielders, as Pistol, Fling, and MR are heavily based on Agi/Sense. While Atrox and Nanomage are not as common, both have their advantages. Advents often end up tanking, so the extra HP given by Atrox are always appriciated, however Nanomage Advents will have the advantage of being able to cast heals earlier, and potentially all of our nanos with stuff like the Professor Jones Vest and Shades of Lucubration.
Bottom line, pick what you think suits your play-style and what you plan on focusing on. All 4 breeds are viable options for an Adventurer.
Adventurers come in two flavors: melee and ranged. The Adventurer profession is very flexible, and has many weapon options. Probably the most popular, however, are Pistol and 1H Edged.
Adventurers have buffs for Pistol and 1HE, in addition to natural green, 5/level skills. Because of this, most Adventurers choose to go one of those two routes. One important thing to note, however, is that almost all of an Adventurer's skills are 4/level, meaning that while you may not get as high a natural skill, alternative weapon types such as Rifle, 2H Edged, and Assault Rifles (among others) are still available options if desired.
Choosing between Pistol and 1HE is a toss-up at the moment, and mostly up to personal preferance. Generally speaking, 1HE will do more damage, and have a wider array of special attacks (Brawl, Fast Attack, Sneak Attack, Dimach compared to Fling Shot and sometimes Burst) but be more succeptible to roots and snares. Pistol has the advantage of being more IP-friendly, making is a bit easier in the lower-levels to spend on nanoskills and others such as evades.
In the end--very much like breeds--pick what you think suits you. Advents will do well under many circumstances, so feel free to experiment if you see fit.
Generally speaking, here is the priority list:
Abilities:
Pick what you want to you for armor, typically based on your breed. Max the two skills you need for armor,
in addition to Intelligence. Maxing Int is a very important habit, as keeping our nanoskills high is key to making sure our heals and morphs are up-to-date.
Always try to keep Body Dev and Nano Pool as high as possible--preferably maxed. HP and NP are very important for an Adventurer, as we will go through plenty of both tanking and healing.
Weapon Skills:
If you are a Pistol user, max Pistol and Multi Ranged. It is not important to max Fling Shot, only raise it as much as you need to. It is reccomended to avoid Burst pistols with the key exception of the Customized Desert Reet. (see details below)
If you are a 1HE user, max 1HE. Due to lower Multi Melee reqs, you may only need to max Multi Melee at the early levels. Remember, it does not benifit you to raise multi-wield skills past the requirements, so only raise as-needed. Fast Attack is very much like Fling Shot, raise as needed. Brawl is usually needed for most melee weapons, and its power is based solely on your Brawl skill. It would probably be a good idea to keep this as high as possible if IP allows.
Speed Skills:
Very important: keep your initiative of choice (either melee or ranged) as high as you can afford. This is a very important skill.
Nano C. Init is a very important skill. If you have spare IP, definitely put it here first. While it is ideal to try to keep this maxed at all times (fast heals are good) it is probably one of the first things to ignore if IP is really tight toward the end of titles. However, if you have IP for it, invest in this skill--it is very much worth it.
Run Speed is cheap, and should be raised for the beginning levels to get you moving at a resonable rate. Most players stop raising Run Speed until they feel like they are moving too slow. We do get run speed buffs, especially outdoors in the way of the Pareet morph, so this is mostly an "as needed" skill. (Buffs like
Terrain Knowledge and
Free Movement are very useful in saving IP here.
Evades are very important in the long-run, but not typically a priority when IP is tight. If you notice MOBs landing critical hits on you very often, you probably want to raise your evades a bit. Most mission MOBs check "Dodge Ranged", the exception being Trader mobs, while check "Duck Exp." It is typically smart to prioritize evades in the order that they appear in the menu: Dodge, Evade, and Duck.
Trade Skills:
Computer Literacy is really the only thing in here you need to bother with. Raise it as you need to access the grid and get new NCU Memory and NCU Belt Platforms equipped. It is probably not essencial to max this every level if IP is tight, however you will probably have to spend on this fairly regularly to equip new NCU.
Nano Skills:
This is a very, very important section for Adventurers.
Matter Metamorphosis: Always max. Used for heals.
Biological Metamorphosis: Always max. Used for heals.
Sensory Improvement: Always max. Used for polymorphs.
Time & Space: None of our nanos use this skill. Only raise as needed to use Nano Rechargers. Typically the rule of thumb is, if your rechargers take more than 3 to fill up your nano pool, it's time to upgrade.
Material Creation and Psychological Modifications are toss-up skills. PM/SI is used for our weapon buffs, while MC is used for our AC buffs and damage shields. Typically, MC is deemed the more "useless" skill when one has to pick between the two. Personally speaking, I would recommend raising MC at the start of the game, as our AC buffs are very helpful early on. However, once you have gotten the 4th AC buff (Major Wilderness Protection) most people advice ceasing to raise MC until later in the game. PM is important to raise as a general rule, try to raise as you can spare the IP.
Let me reiterate: make sure you
always raise MM/BM. They are, by far, the most important skills an Adventurer has. Heals are our lifeblood, and it is integral to keep them as up-to-date as possible.
First Aid: Typically viewed as a low-level and high-level skill only. Not a very good use of IP for most of the game.
Treatment: Very important skill. I would recommend maxing if at all possible. Adventurers have the cheapest Treatment in the game (along with Doctors) and therefore have a large advantage in using Treatment Labrotories and equipping high-level Implants. It is a very good idea to take advantage of this, and keep it as high as possible. Adventurers will always have a leg-up in the implant department, which really helps out.
Navigation Skills:
Raise Map Navigation as needed for the maps you want. Try to get the first 3 or 4 Map Upgrades as soon as possible, then ignore this skill for a while. Not terribly important once you can upload the common maps. (130 is usually the stopping point here for the early game, which will allow you to get Map Reader Upgrade - Monsters and most of the basic maps.)
Due to the map nanos found Shadowlands, Adventuring is now a bit of an important skill, and perhaps Map Navigation is less so--depending on how much time you spend on RK vs. SL. I would recommend raising Adventuring as-needed to cast the map nano for the playfield you are currently in. You may also consider using Adventuring-buffing items (such as the
Signet Ring of the Green Knight,
Ring that Turns Rocks,
Globe-Trotter Helmet, and
Mitaars) to cast these if you can to save IP early on.
You will probably want to raise Vehicle Air to use a Yalm around level 50-70. Find the lowest level Yalm you can, and raise this skill as little as possible.