"Oh, what a tangled web we weave when first we practice to deceive." - Sir Walter Scott
Here's how we did it in my situation. I've been through this *separation* thing a few different times and in a few different forms.
Re: her just *popping over*.
No. It caused me a lot of anxiety and made me incredibly edgy when he would just come and go as he pleased or just *show up*.
Yes. Get a schedule put into place so that the children know when they will be with your WW and when they will be with you. This is really important for your kids right now when things are kind of *in flux*. If you have kids that are older than 16, you can allow a bit of leeway on this...or not. I didn't until my oldest was 18. The *bonus* of having a schedule is that there won't be any type of *he's keeping the kids from me* if/when she calls at the last minute wanting to see them, but you already have plans.
I got nothing for you here. Our shit is so complicated that it was *easiest* to just leave it status quo until we get the D logistics sorted out. If I had to do it over again, I'd put a 'cap' on spending, though. If either party is going to spend over $X, the other spouse needs to be notified. Not that Sultan would have abided by it, but I should have done it anyway....
If the status of your future is truly 'undetermined', you might want to consider paying lip service to whether dating other people is allowed during this time period.......
In my effort to be *concise*, I often come off as blunt and harsh. Sorry, don't mean to be offensive.