<human>: Condense the text into a few key points

I have a 5 month old aussie pup and he is the best thing thats happened to me since I met my (soon to be) fiance. I've done a fair bit of reading on the breed and dogs in general before and since I picked him up and one of the recurring conditions to try to avoid is, i guess, over devotion? Something along those lines, the term escapes me.

How can i avoid him becoming an anxious mess if i have to leave him for an hour or so.  I don't think there is an issue as of yet, he likes his crate most of the time(there was an incident involving a destroyed set of sheets and my favorite comforter.) What i'm worried about more specifically is how he acts when i leave him with my GF. Even if i am simply taking the trash out i hear him wine and yelp and hit the door bells.

The only time he DOES'T do this actually is when i crate him. I've read and accepted aussie being shadow dogs, as in, becoming your shadow and i love it. I didn't buy a dog to leave in the yard all day or leave home when im hiking or other fun stuff, but i do want to know what the acceptable margin of exposure to give him to solitude in the event that i DO occasionally have to leave him. I'd just like to avoid the anxiety for his sake.
<bot>: how much time should i give my pup away from me to get him used to day to day errands and have a healthy attitude to me going to work and whatnot. '