I never used to be fussy on seats but got a sdg bel air mk3 and it's noticeably more comfy than the maddison flux/fabric scoops I usually have.
Bike looks neat as always fella
Non boost, in a buyers market probably 500 ish for the orange. Probably best splitting.
As for those parts, chain reaction still selling deore brakes 30 quid an end (or were not long ago), bashguards aren't really of value second hand. Most of those parts I'd just whack on eBay and hope for the...
Photos would help. Not sure what parts there are hard to find these days though? Saddle maybe. Jump bikes don't sell well especially higher end as people either build their own or want to pay peanuts
Yes, left side, around the headtube and into downtube on the right. Droppers can be sensitive to tight turns. If I recall, I didn't have grommets either so bought some ragley or other ones and bodged it