On 1, as it's your guitar, it's really up to you. If you want it to look like a vintage Gibson, then look at photos of similar models (heel pictures are hard to find but they are out there) and see what they do, but the bottom of the heel is normally flat with a fairly well defined edge.

On 4, as Brendan says, there's no real way to shield the electrics as on a solid body. If noise is an issue, you could look at getting a replacement metal covered dog-ear P-90 which will help. Using shielded cabling for the signal wiring will cut down on a lot of noise pickup and produce almost the same effect as shielded cavities will, as it can leave very little of the signal wiring exposed. You haven't got a pickup selector (which normally adds a reasonable run of cable to a hollow body build), so wiring lengths are already quite minimal.

On 6, There is a Dingotone Guitar Wax which can be used of rosewood fretboards if you like a slipperier feel to your neck, but personally I use lemon oil. It needs re-applying from time to time. but it's a good reminder to check and clean your fretboard and polish your frets from time to time.