Hello and welcome to YT. I don't think you are messing him up by allowing him to sleep in his bed provided he isn't making messes and sleeps when he is supposed to. He probably does not want to go in his crate when you leave because he now associates the crate with you leaving. I think it is great that he is scheduled for his neuter. No advice there - had Jack neutered when he was about 6 or 7 months old and he is almost 4 so I can't remember too much about it. I know you will want your vet to do blood work prior to the surgery - and I am not good with all that information, hopefully one of our more seasoned members will come along and help with this. When you leave to go see your grandbabies, he will be fine and will be glad to see you when you get home. Thank you for rescuing this little man.