Mistake number one!!
"None may judge of the craft, but the craftsman".
George Silver - 1598!
OK, my mate George there *was* speaking of swordsmanship, but the same lesson applies everywhere. If you want opinions, get them from people who know what they're talking about - ie Bikers, first and foremost.
Second - You'll find that any biker worth his/her opinion will tell you that their opinion doesn't matter and it's down to what YOU like best!
If you like the carpeted seat, keep it!
I've not seen one like this myself, so you have a very unique and cool-sounding set-up already. Out of simple curiosity - I would ask what you'd do if it was raining, though?
Personally, I went the opposite way to Kindest here - I started out with a pristine, shiny Cruiser all chromed up and gradually let it get a bit mucky (mainly because I rode most of the time and had no daylight left to clean it).
The mods I made were almost all purely functional, with the sole exception of adding a rubber cover to my rear brake pedal plate. I choose function over form any day and rather like the 'tacked-on' look. Eventually I will Rat this bike up and make it a proper "Does Stuff" kinda thing!
Bottom line, ride what YOU want to ride and the instant someone starts telling you what you "should" do... Tell them they should shut up or face the consequences!!
If they want to face the consequences, a good one is to drink them under the table on their credit card - They'll soon learn to keep quiet!!