Yes you can. Can't help you with specifics as I don't use Jamba. But can't be hard to figure out. (remember u need to be lvl 10+ in order for Jamba to work properly)
No, you won't farm that much per day. Even with a 40 man team it will take you hours to farm just 40k (not talking about weeklies, rather daily farm.)
If you already play here then you know what costs what, not hard to do the math of what you can earn/grind. Spamming daily quests can give you some good gold but keep in mind that it's boring AF and very time consuming.
Pretty much the same stuff as any "X"-man setup. Bg's/world PvP/PvE. It all comes down to personal preference
Don't get your hopes up for raiding 10/25man without or even with gear for that matter. Due to how the game works it is rather hard to manage mechanic wise, stepping out of aoe's and such, handling boss mechanics etc. Don't think because you multibox you can tank and spank everything, you still need to use the tactics that any normal raid would need to use, wich makes it harder for us, if not impossible for some instances.
I suggest if you do wish to do bigger raids, try it with another boxer. You can split up the loot nicely and you have better chances.
Yes it's very much possible to farm your own gear with gold but keep in mind it's not an easy "1 month job" this will take time and dedication just like as you would do it on a solo char.
Brawling with other boxers is the most fun for me or playing AV/IOC completely alone (As I play 40-man teams)
WG or weekly 25 man raid(soloing) is fun too but gets boring really quick.