If you can stomach crafting/gathering, they are really good sources of income. Gathered materials you can sell in the wards, especially logs/branches. Just make sure that you price them less than the NPC that sells them (if it is sold by an NPC). Check out mooglebox.com or yg.com if you need that sort of information.

Crafting, especially when coupled with a gathering class, is an absolute gold mine as long as you play the market. This might be easier to read once they add the price history next update. Take a look at what gear looks most desirable, what seems to be selling often, or what is out of stock. If you don't completely jack up the price of something (like charging 100k for a level 8 weapon), you should see some noticeable income, especially if you gather all the materials. Once again, check NPC prices and sell for below them.

Also, guildleves provide more relevant material rewards now, so after doing a couple leves you usually end up with enough raw mats to make a few items to sell in the wards.

As far as leveling a battle class, keep in mind that under the direction of the new team, crafting and gathering are going into more of a supportive role instead of active participants in the main storyline. As it is now, the game is starting to become more centered around Grand Companies, which require a battle class of at least 20 to sign up. The main story content is all going to be more action-focused to give players more satisfying and challenging battle content. Crafters and Gatherers are going to be getting their own content, but it is further down the line.

My advice would be to try out all the battle classes for a few levels (especially after the patch the middle of this week, when the classes are seeing some major revamps). Not only will you pick up a variety of cross class skills, you will get a better handle of what you might have more fun with.

After that, keep an eye out for parties in shouts, ask people at camps to team up, and after this coming patch, make use of the party search feature to meet people and ask to join their linkshell if you find anyone friendly. With some teamwork and the right camp, you should be able to get great XP at any level with any size party. Good luck!