A nice TLR is a very good camera. I have a Yashicamat 124 and a Mamiya 645 Pro. The Mamiya is way more versatile with its interchangeable lenses and film backs, the latter allowing film changes in mid roll all you want, and it's AE Prism finder and motor winder grip. It's really just like shooting with a very large 35mm motorized SLR, plus easy mid roll film changes. But I enjoy the Yashicamat more. It's much smaller and lighter and easier to carry when doing something else, even accounting for also carrying my Luna Pro SBC light meter, which is a big handful of meter. No midroll film changes and no lens changes which can be limiting but can also be "focusing" - use your feet to zoom (not always possible though) and decide what film you are going to need for what you are about to shoot. If you can live with the fixed lens and no mid roll film changes and think you'd like one, go ahead and get a good TLR. If you get a good one and don't like it you can almost certainly sell it at little if any loss.

I stick the tape down all the way too. When ready to process I peel the tape loose with the lights on. I just hold the film and backing paper down with one hand (you have to hold it anyway, just be sure you hold the end down) and peel the tape with a thumbnail on the other hand. Once the tape is loose I can turn the light off with the hand that just peeled loose the tape and then load the film. Easier said than explained - there's nothing to it. Loading the 120 film on a reel takes a bit of practice but you'll get it down and on some reels anyway once you get the hang of it it's easier.

Just how expired is the E100G? If it expired in the past couple of years and has not been stored in hot conditions, room temperature or cooler, I'd just have it E6 processed. If it's very old, that's different. You can cross process it, but bear in mind that people do this for the wild color and effects and you aren't going to get a good comparison of formats comparing that to normally exposed and processed 35mm film.