Hi Chambo .....
Most insurance companies consider implanting the abutment as a prosthetic device and therefore will cover the cost, even if done apart from your AN surgery. I doubt if your insurance company would approve the cost of only the processor, without the abutment.
As for wearing it only occasionally ..... you really need to wear the processor (the Ponto) most of your waking hours to get the maximum benefit. Hearing is really a "brain" thing, in that one's ear (or processor) is only the conductor of sounds to transmit to the brain for understanding/use. The more you wear the processor the better the brain will adapt to receiving/interpreting sounds from that side.
I put my processor on right after my shower in the morning and rarely think about it again until I remove it to sleep. Obviously, I need to remove the processor for any swimming/water activities and I am even careful to cover/protect it from rain, etc.
As for infection ..... I try to be very diligent to brush (with the soft brush provided) around the abutment at night, especially on a day I may not have washed my hair. Every now and then I will experience a mild irritation around the post, but a wipe around it with peroxide, followed by a tiny dab of Neosporin, clears it up by the next morning. I have traveled extensively with no issues.
Hope that info helps.