I haven't suffered any of that and I've been jailbroken on 9.0.2 since it was released (the very day).I dunno about the 9.1 JB, but the 9.0.2 JB is pretty solid.
My phone will randomly power down about 1x per week. Still haven't identified the exact conditions...at one point, it seemed shaking the phone vigorously did it.
Never suffered BLoD or anything like that. Been very solid for me.
Huh!9.0.2 is so damn unstable it isn't even funny. My fiance's old 6S was jailbroken on it before she demolished the phone Now my SE is (obviously) on 9.3.1 and it's stable as can be. Hope one comes before iOS10 but if it doesn't it, at this point, I just check r/jailbreak once a day and then resume business as usual. I hate stock iOS but there are a few things I can do w/out a jailbreak that a lot of people don't know about.
All the legacy devices are still jailbroken along with one of the Air 2's.
My wife's 6s is jaillbroken on 9.0.2. I have heard zero complaints in the last six or seven months about stability or anything else. My usual problem with her is trying to get her to restart her phone from time to time.
My own 6s+ has been rock solid and I have over 160 tweaks installed.