1. It depends on how you want to run your offense. If you want Odell to line up in the slot in 3 and 4 WR sets then put him in the SLWR 1 spot. Even if you also have him at WR1 in the normal depth spot, if hes SLWR 1 he'll line up in the slot in 3 and 4 WR sets.
2. If you have a SS that has good coverage skills and is athletic you might use him as a SLCB, it depends on what the rest of your roster looks like. This works the same as SLWR, no if you have Eric Berry in the SS1 spot and the SLCB1 spot in the depth chart then in Nickel sets he would line up in the slot and your SS2 would line up at safety. I usually don't use safeties at SLCB because they normally aren't as athletic. I do however use a safety sometimes at one of the SUBLB spots if I have a bigger stronger safety and not many linebackers that are good in coverage.
3. If you have it set up this way I'm not sure which side the game would actually line him up at but it would just line up who is in the 2nd spot on the other side. Personally I would change it and set put someone else in the 1st spot in one of the sides.
The answer to all of these questions really just depends on how you want to run your scheme. Or example I've used my number 1 WR in the slot on some teams if he was a smaller slot receiver type and I had other bigger receivers lower on the depth chart that would be good for the outside.