Well, I'll give it a try too- I have a perm end ileo with my rectum removed & sewn shut.
1- nope, I'm 5'5", weigh abou115, but I eat all the time- far more than I ought to for weighing not that much! I don't seem to put weight on that easily, but I never really did.
2- I hike & bike a lot, & often go 4-6 hours without emptying my pouch. It seems like it fills up overnight, I have a full bag in the AM, then I empty maybe 4x thruout the day, until bedtime. This is reagrdless of what I eat.
3-I had surgery at 44, am now 45- still young! I personally felt only capable of dealing with the one major surgery.
4- Immune system seems fine- I'm in the "auto-immune disorder" IBD camp, so always wonder if it's going to attack some other part of me- so far, all's well.
5- could not handle this symptom, after going thru such a major surgery & still have daily issues to deal with.
I love the ileo- of course, would rather have been able to not get one, but... you think it's going to be such a huge change, such a big deal, then it happens... and it's not! You wake up from surgery, think "That's kind of gross, and kind of cool", then just move on. I was actually shocked that I never did have that freak-out moment... I eat what I want, I go wherever, whenever- I'm active like I never could be with UC, truly have zero restrictions on my daily activities. Good luck, whichever way you choose!