You have some excellent questions. I hope I can help. Here we go -
Sharp - I am not a big guy on shaving sharp for an axe. Dont get me wrong, the sharper the better, as stated, a sharp axe is a safer axe - no glancing blows, etc. How sharp is ultimately up to you. I dont get too crazy with the hair shaving part because my thought is, after about 1o swings, that is usually gone anyways. So I pay more attention to the profile, as in bit edge, back to the first edge, back to the cheek....if this is correct, you will have a hell of a chopper. If it is too thin, or too thick(v shape, see Fiskars), then you have a splitter. It will really depend on what you are doing, wood size etc. There is no absolute answer, IMO.
It should come convex, as in thicker back to the main cheek, this will enable better splitting and rough use. GB does not have this - they are pretty thin way back - and is usually not fond of with the regs around here - but it is preference really as is most things. For me, out and about, I want a beater more than a looker. Thats just me.
Oil - oil her up. Head, eye, haft, etc. Yours will come in with a light coating of linseed on it, which is good. Caution - too much linseed will make you handle sticky icky, so less is more. Some guys like to dunk theirs in linseed for a couple days and pull out - I myself am not for this but i am not 100% up on the total method. I like many thin coats over time. This is more work, but to me makes for a better end product. Again, one mans way, I have no issue with the big soak. Side note - if you have linseed soaked rags, you need to make sure they are well ventilated - do not roll them up and throw away - there is a combustion hazard - burn them right away, or soak in water, or I hang mine up for good ventilation. Don't skimp in this - they will catch fire.
The axe you have will do what you make it to - it just might not do certain things well, thats all. It isn't meant to take down a 16 inch maple. Up to a foot you can handle if need be, but that is probably asking about it, again IMO. It is meant for lighter work overall. You get into too big of stuff and all you will do is tire yourself, then mistakes happen. Technically, you can fall a huge tree with a hatchet if you do it right, its just a question of whether you want to, and if you have the time.
Hope this helps!!!
Thanks!