Enoree has some area's in it that wouldn't be a problem on a GS but then again there are a few spots that I wouldn't attempt. I would advise at least walking them first and making up your own mind. The trail seemed plenty wide enough for my DRZ but that is a far cry from a GS. The trail surface at Enoree is clay base and shouldn't be a problem with 90/10 tires,Manchester is nothing but sand and even DOT knobbies aren't fun. Full on knobs or paddle tires are required there.
I've also done Parsons Mountain and found it to be the easiest out of those three, I have not been to Cedar Springs so I can't be of any help there.
Also remember the "Call before you Haul" hot line. I've ridden up there and found the trail open after a deluge and found it closed after a light rain, doesn't seem to be any rhyme or reason when they decide to close the trails.
I have some armored gear you can borrow before you attempt these trails, don't know if they would fit you or not though. I'm 6'2" and 210lbs with size 11 boots though I normally wear a 10.5. I found the larger boots more comfortable. Your welcome to use the gear until you can get your own, I'm located in Lexington.