1. No. You must "befriend" it there.
2. Forever. You're better off trading for one. I'll try trading for a goldeen and getting it to you soon. You'll need a female one.
Note: Later tonight I'll pick a BP for you to do and provide the DW female, if you'd be up for doing that first.
3. Not yet X( But I have a bunch of others (See the first post in my thread) that I can provide for parents if you need them.
Note: I require perfect 31s, not "30s" unless they're there for HP bonuses. I hope you understand.
Creditwise, I think 4 credits would be fine for a shiny - but I'd like a copy of the egg to hatch a non-shiny version as well. I'll EV it myself (I'm an expert G5 Ever, so if you need EVing let me know).
Why don't you CMT and see if I have any DW females you'd be interested in breeding with.