1. When is an appropriate level to start crafting.? I am in the process of leveling my thf to 50 (for sub and farming) and would like to know when is a good time to start?
Anytime, really. I had a level 60 craft before I had a level 60 job when I first started (but then again, the game was very different at the time). I'd recommend starting with cooking and maybe a couple other skills just to see if you enjoy crafting. Really, the most important thing with putting time into crafting is either a) you enjoy it or if not b) you just want to "complete" everything.
2. Which crafts compliment eachother? I was thinking I would start with alchemy and fishing I plan on leveling cor so the alchemist is more for use the profit, I plan on at least getting alchemy to 60, then moving on to cooking and woodworking. the wood working isonly for arrows anr arrows and tools so that won't go past 60. Which crafts should I consider taking past 60. Other then alch and woodworking which I'm going to be using for me the rest all seem so valuable its hard to pick?
First, realize I do not consider fishing a craft and all of my advice does not include fishing. It's not a bad "craft," but it's not really crafting either. As I mentioned before, I suggest cooking or alchemy first as they are probably the cheapest of them all. If you absolutely despite crafting after that, don't continue as it won't make you rich.
As far as what supports what, the combinations are really too many to list. The big one I'd like to mention though is leveling bonecraft and clothcraft before woodworking. Alchemy can help with skilling goldsmithing as well.
If you want to make Corsair your main job, then high level alchemy (and goldsmithing as a sub) is a good idea for making bullets.
If you want to be a major crafter, you will need
to level synergy, it is just that important now.