Good decision!!!
he has asked me to transfer him a big chunk of our savings as in ‘his half’ but I’ve refused to do this as I know he’ll just drink and possibly gamble it away, who knows.
I assume I’ll need to speak to someone about the legalities of untangling financial assets, having supervised visits (if he even requests to see our lg, he hasn’t mentioned her so again who knows)
CAVEAT: I'm in the US, so things may be a bit different there.
If it's a joint account, here you are not 'required' to transfer jack shit. If he wants the money, he can (and will be able to) go get it himself. In fact, he could clean out any joint account if he's a mind to. For this very reason (we had joint finances) I was advised to transfer half of everything into an account in my sole name. And it was a good thing because DH did empty the accounts into one in his sole name. But I'd already moved my half and changed my direct deposits/direct debits about a month before. So if we are talking joint accounts here, you probably should take your half (and only half) and move it.
If it's in a sole account, my understanding (again US) is that you still don't have to transfer it upon his demand as 'technically' any money in a sole account belongs only to the account owner, but obvs do not touch that share of the money. The court can and will decide who gets what.
So, yes, you need to see a family solicitor ASAP. I did and it was the best money I ever spent. I was given the information I needed to 'untangle' our finances even before any legal papers were filed. This made the legal separation much easier as our finances were already pretty much separate and all the judge had to do was 'confirm' them. A legal separation (at my age) was better for me than a divorce as far as my future finances are concerned. This is probably not true for a younger person and when DC are involved
As far as LG, my understanding of UK law (which is similar to US in this respect) is that barring a legal order, the parent who has the child doesn't have to let the other parent see the child, it's a case of 'possession is 9/10th of the law'. Now, whether or not withholding contact is wise in the long run is something to speak to a solicitor about. You have very good reason for not letting him see LG. A solicitor can advise you whether you need to go for orders or 'let sleeping dogs lie' as long as he isn't asking. The other thing with no orders is that if both of you have PR, either of you can keep the child from the other. So the likelihood of him 'getting' LG somehow and refusing to return her is something to discuss too.
Trust me, good legal advice is worth its weight in gold. And it may seem like you are paying 'in gold' but you'll be happy you did. Write down family finances, whose is whose, income and expenses, and assets and take it with you.