I am in the same boat, as you know. What I do, is keep finance discussions to a minimum, as thats not really the 'issue', as in, any awkardness/emotion I feel is to do with us being former partners and him having left me and not really to do with money. So maybe just examine your feelings first off.
Secondly.. are we talking large sums? If not, can you cover the bills/debts until he does get back to you, even if that means he ends up owing you? Again, I have covered things and my ex has paid me back (usually promptly) rather than chase him on occassion and I was mindful not to use that urge to chase as simply an excuse to have some contact with him and I had to be really honest with myself there.
I'm confused on the finances though.. you say you WERE on a payment holiday for more than a month in the end, so Christmas until March and you asked if its ok to resume payments, on an interest only basis?
If you are selling the house anyway, there isnt any need or benefit in resuming payments in fact, you could take advantage of the whole 8 months, and I guess you know that, which might be why he hasnt replied (I would be confused, if I were in his shoes)... the unpaid interest just gets tacked onto the overall amount owed.. which will then get paid out of the profit of the house sale once you redeem the mortagge. There isnt any penalty for doing this and as you are selling within months/a year hopefully, you wont really pay much extra interest overall for the privilege of having had a slightly bigger mortgage after not having paid 4 more months of interest on the loan. Yuo do realise this ? So.. no need to send those forms off yet?
As for him not paying into the bank for bills/debts.. again, what bills are these? House insurance? There cant be many things he has to contribute towards now he has moved out and I doubt its large sums.. so I would wait for him to get back to you and I cant really see any need to meet him to 'discuss it'? Worse case scenario is, you would keep a spreadsheet of costs you thnk he hasnt paid or owes you and you can take that off the bottom line when the house sells, again, unless you cant cover the costs in the interim? He did let you know he received your email but was busy, thereby implying he will get round to it !
I agree, we are the ones who have to be financially responsible and its annoying and not fair, but it is how it is. We are the grown ups hey!
I know it sucks, I havent seen my ex since November and I cant really make him want to see me. Same goes for you. But if you want to see him, I would be brave and suggest a catch up drink or lunch sometime and not make him meet you to discuss small matters of finances. He might feel arm twisted by that?
Lastly.. me and my ex have tangled finances, he managed to send me half for a landlords policy the other day, but not for half of a boiler check, but as it was only £60 I didnt bother asking him for half. I know its 'right' to split everything 50/50 and apportion costs, as you say, now we are split.. but sometimes Julia, you just got to let it go, chalk it up and realise that money is the least of it. The real issue is the loss of an R and a potential future with someone you loved hey. IMHO.