You should put together your musical bits and pieces in as fast rate as you can. Maybe 3 verses and 4 choruses a day?
Make sure you have access to a solid bridge. To jump off of, in case you don’t get it to work. 
This has to be the funniest statement in this entire thread.
“Your e-peen is strong, young Skywalker.”
The issue of dithering is something I do worry about. Cubase uses Apogee dithering (in a plugin) while Wavelab has the better iZotope dithering plugin. In the iZotope demo recording, you can hear the difference but in my testing using Apogee, I can’t hear anything different during the fade. It’s just one more thing to obsess over I guess.
Dithering is another issue (not directly related to sample rate conversion). I was referring to this:
http://src.infinitewave.ca/
go as high as your system can handle and running stable
What ever sounds best, to You. Some AD/DA sound better at a lower or higher rate. Some plugins sound different (better) at a higher rate, and a combination of all these parameters makes it hard to give any advice other than.
Test test test, listen listen listen , make a decision and be confident in it. That way you don’t have to worry, until you change your gear again 
48kHz sampling rate is more than fine. I used to record in 88.2 and 96 back in the days myself but there’s really no need to. It requires so much computing power and produces monster files, and at the end of the day, no one really notices the difference. I mix in 32 bit float.