Perhaps someone more knowlegable can answer this, but how much can HRT fuck over a man's health? Particularly a fat man like Jim. I was under the impression that a man needed a reasonable level of testosterone in order to stay healthy or at the very least not feel like shit all the time. It just seems like you're speeding up the aging process when you do that to yourself.
From personal experience with the thing, there doesn't seem to really be problems with being on female hormones with the right dosage, however being on the wrong dosage actually does result in bad things (I mean, not cataclysmic, but it definitely isn't a great time, and it's kinda surprising what it can do), and there may be a transitory period* where you're left without hormones at all and that is pretty brutal (Menopause, but ironically on steroids).
I do think weight becomes a bit harder to control overall, especially when you have no hormones at all, but it's still calories in, calories out, and obviously, in the case of the transitory period, you can just lose the weight afterward, it's temporary. As an anecdote, and I would assume this "data set" is very biased because the better your weight the more likely you are to mention it, but a decent majority of the time, when I've heard trans' people mention their weight, it was underweight (Not clinically underweight, as in, super-thin, though there were cases, I just mean below the average 21 B.M.I. by at least a small margin), which makes sense, you want a thinner figure for good passing.
As a last point, I would mention that S.R.S. (Bottom surgery) doesn't work too well on fat people (I'd assume no surgery really does, but I guess one as delicate as this in particular, I've even heard of some surgeons raising their prices past a certain B.M.I.), and obviously there are very good reasons to lose weight before even considering that one for Jim, but his recent mention of his d#ck did make me think of that as a potential impetus - but more potential than anything, hence why I didn't make a post about it back then.
*: I.I.R.C. part of the reason why it's done is to have a "psychological buffer" period where you start losing effects of testosterone and stuff but don't start a female puberty either, to see if that's really what you want, so I'm not sure the U.S.A. requires trans' people to go through that or, if you asked, they'd just allow you to switch from one to the other directly. So not sure Jim actually has experienced that.