They are cuties! As to leashes...I would suggest a harness-style vs collar for them as they are so small. And probably a small, thin, cloth or rope type leash as opposed to a chain-style leash. You could also get a leash connector thing. Attaches to a single leash at one end and then has two leads for the 2 dogs. Helps control the this way - that way bit. They probably just are not used to collars/leash at this point.
Housebreaking...we've always gone outside with them for the duration until the finally get the message as to what 'outside' is for! Basically after each meal, as soon as they are finished eating, take them out for walks until they have both finished all their potty needs. Give small treats each time to reinforce the 'good girl' message. Any time they start to 'circle' or start looking intently inside, scoop them up and run them outside. Might be easiest to leave the harness on them full time for the moment and the leash available outside so you can get them out the door quickly for those type trips. Complete housebreaking usually takes a few weeks of tremendous diligence.
You've only had them for a few days and it sounds like they've had quite a bit of trauma already in their short lives. Once they get comfortable with you the constant need to be held will abate. Give them a soft, safe place to be when you're not in a position to hold them. Tell them 'good girl' when you put them them. They'll get the message sooner or later.
I'd also recommend a crate for those times when you are not home to help with the housebreaking. Obviously does not need to be large for those tiny girls. We've always given ours a treat when they go in their crates so they know it's a good thing. Soft bedding - just old towels will do. This way, if there are accidents...easy clean up.
I get what you mean about the big birds! When we got out latest dog he was 8 wks and 15 lbs. Certainly much larger than yours but I was still worried about the turkey buzzards swooping down on him. And we had coyotes in the 'way back' at that point as well. Wouldn't let him out of the fenced yard even at that point. He's now 2.5 yrs old and 150 lbs. Not worried about the buzzards with him now!
Just remember that you are dealing with tiny babies. Little tummies; little bladders. They'll sleep alot. Each time they wake up....out the door!
Good luck. You (and they) will get there!