just to add my 2 pence in, currently 5000hr + capt with large uk airline but began gliding. I`m silver C with 2 gold legs. gained ppl from silver c conversion and became tuggie as poor 17yr old wanna be airline pilot.
great fun, but very hard work.
hours great on paper but useless for future airline credit. Gained hundreds of hours and caa gave me 5 hour credit for them doing an approved cpl course.
(fine for the self improver route but airlines like 509 students (or what ever it is called now))
Gliding experience is definitely required. Best tuggie`s find lift all the way up, dropping the glider in the best lift upwind or being considerate of his planned task. Is able to use lift to get the combination up quickly using less fuel and then (after a very careful engine cooldown regime) get back to the launch point while negotiating the gaggles.
gliding clubs are fantastic places, everyone pulls together, great atmosphere and always a bbq, beer, pub meal on the way back from a retrieve.
learning curve is steep, keep the release close to hand as it goes wrong very quick. From a glider ground looping behind you or going too high and pinning you on the deck all require giving them both ends of the rope!. As a resident tuggie you may be allowed to do aerotow retrieves. These are limited to mostly airfields now days but you may have to do a field retrieve. A sound knowledge of field landings and aircraft performance is needed. Its also a hard thing to arrive, decide its not suitable then give them a big bill. (you always ask them to walk it, check for cables etc, then find its 300m shorter with HT cables on the approach

!!!)
doing 6 tows an hour with a k13 boxing the wake becomes very tiresome!
You will be able to platt a rope in about 30secs
You will get to fly some fantastic aircraft. (and clean, oil, fuel, help fix, clean windows etc)
You will love every minute of it!
You will be everyone's best friend if you put them 6kts+
You won`t make money from it as people love doing it and it is free flying!