I have had some annoying MS account related issues on our new laptop (whilst our desktop works fine with our family accounts). See User account and family issues. It's made me consider on the laptop to convert my main administrator MS account login to a local account and dispense with multiple user accounts on it. However before I do this I wondered about several things ...

1. We have several user accounts on the laptop (all MS / family linked). Presumably I need to delete these other user accounts first - Or what happens to these if I don't. Seeing as the account I plan to turn local is mine and I am 'head' of the family. If I delete them normally I see the rest of the family listed under family settings as 'Can Log In' and allow them. Will this listing disappear under settings if I convert to local?
2. As the whole MS / family setup works perfectly on our main desktop PC I hope there is no knock on effect towards the whole multi-user family account setups on here. I'd hate to do the change on our laptop and some nasty side effect to rear it's head on the desktop. It should remain untouched and still list our family under 'family settings'.
3. With a single local account setup on the laptop what happens if I want to use the store on it? Can I still buy apps, films, music etc? Will existing apps I had previously downloaded still work? I am probably wrong but I was under the impression you had to be logging in with an MS account rather than a local account to use it?
4. Can Cortana still be used for interests etc on a local account - I'd still like to see weather / headlines etc
5. MS Office 365 login and onedrive - do these still work ok under local accounts?
6. The final most important thing I don't want to upset - iTunes and all my music on the laptop. My iTunes library points to my existing music folder under C:/users and is all iCloud / iTunes match enabled. I worry that the user account change to local will unsettle all of that. Especially as the library points to files in a specific location. My assumption is the change to local will change my name under C:/users, therefore iTunes won't know where to look (or it will) and report ! next to all the songs as it would of been expecting to find them under my old user name folder - hope that made sense, hard to explain.

Of course I'd rather not make this change and keep the multi family accounts setup on the laptop but the user accounts are proving frustrating (as per my thread link at the top) with intermittent long delays accessing anything MS account related every 24 hours for some reason. My son can barely use his as due to being a child account edge (and IE11) is taking upto a minute to become useable for him, presumably as it waits for MS servers to track his activity. I don't know whether to blame MS servers (seems as if they could be to blame) or the laptop is glitching (maybe next cumulative update will heal the grief as it's only couple weeks old and hasn't had one since initial setup and of course around that time languages/speech packs were being setup, lots of installations etc so it could of got itself into a pickle)