Hibernation is a controversial subject and many people have strong opinions one way or the other. From what I have seen, they are fine if you do, and they are fine if you don't, but in either case, it must be done right. If you don't hibernate them, you are going to need a large indoor space for them.
As for them living outside full time, I don't go by age. I go by size. Usually around 4-5" for DTs. My preference is to have a large suitable indoor enclosure where they can live full time if need be. Then I make a large safe outdoor enclosure and put them outside in fair weather. New hatchlings only go out for an hour or two. As they gain size they stay outdoors longer and longer each day. By the time they are around 4" I usually put them out in the morning and bring them in at night. I wait for late spring time to move them outside full time and I make sure they have proper housing outdoors too. Either a heated secure night box, or an underground "burrow" of some sort.
When babies are started dry as yours were, they often grow much slower than "average", but not always. So you might need large indoor housing for two or three years.
Well I've started soaking them more frequently and for 30 minutes instead of the 15 minutes I had been soaking them for. They want out of the bin though. I don't think they're happy with me at this point. LOL It's only been 2 days with their new routine. Can I expect to see any improvement in their shells or is the damage already done and what I'm doing will just prevent them from getting worse?
This is the one that didn't even open his eyes when I got them. This picture was taken in May, just a few days after I brought them home. He looks so sick and he was. I thought I was going to lose him. Now he's all over the place. This picture also really shows the extent of the pyramiding which until you told me I didn't even know wasn't normal.