When the freezes happen, do you see a green or blue (proxied) light in the right bottom corner or two arrow forming a circle?
I wish I had seen this post before I tried everything else, but no, I don't remember!
When your Electrum has a blue light then you go through a proxy, possibly through Tor if that's configured. Tor can sometimes be quite slow which might then explain your freezes.
Tor or opennet, both where experiencing issues.
Problems can (but most not) show up when your addresses have a transaction history that goes into the thousands. If that's not the case for your wallet then something else is fishy.
That log that ends with "receiving history" also made me think the same.
I don't have thousands but I have +500, I don't know if the number of outputs and inputs matters but there is a ton of them, not simple tx, and this was probably, like 99.9% why it crashed. I played with an old virtual machine with an old electrum wallet I had, same version and it worked flawlessly but I had under 10tx per adress.
There is an advice about not reusing addresses that I should have taken seriously but it's so hard when running a business to keep changing your little cold storage.
Despite me being really later, thanks for the the comprehensive answer, 6 years and this forum is still better at getting replies that others like stack or reddit.
I can't recommend one as I use my own fast Electrum server for performance and privacy reasons.
Noted!