Coventry is the only airport that does not have specific "Scheduled" or "Charter" flights, all flights operate with the low-cost airline formula. All other bases are essentially keeping their charter operation formula, but are selling seat-only at attractive low-cost prices. As far as I'm aware there are no differences besides CVT crews sometimes have a four-sector day, whilst most other bases only have two.
When you apply for a specific base, you will be trained on the aircraft that are based there. I've been trained on the 737s for the CVT base, although having previously worked at EMA have 757/767 training. Am not sure whether new recruits are now trained for all types but don't think this is the case.
I recently heard that TOM want all shorthaul flights to operate with a no-frills, fast-turnaround, cabin-tidy approach - rather than bringing on cleaners. Personally I can't imagine any Greek airport or some Spanish ones managing with a 30-minute turnaround.