Would I be able to hit 400 crafting on my lv 40 alt (that I don't feel like leveling)? Or is the crafting tier somewhat restricted to level or something. I can max deploy 5 companions atm.
Yes, all that is required is to get to the fleet so you can pick up the crew skills and crafting skills.
If you're only level 10 you will only have 1 companion deployable, but since you're 40, you should be able to use all 5.