Authentication methods for home network shares

I have a very basic setup:

MediaServer: Windows 10 - Running StableBit Drive Pool

Has a number of shared folders:

• Movies
• Photos
• Videos

LoungeHTPC: Windows 10 - Running Kodi 16

BedroomHTPC: Windows 10 - Running Kodi 16

Laptop: Windows 10

I've used this setup for a while but since windows 8.1 and now 10 whenever I reboot one of the HTPC's or laptops it takes an age to reconnect to the server. I get a message: Windows Cannot access MediaServer (0x80070035) and it stays like that for a while before it finally lets me in. I don't have to do anything except wait for 5 minutes or so.

I've set up accounts for each family member on Mediaserver mirroring those used on each device that connects e.g. my Microsoft Account also has a profile on Mediaserver.

Each PC was connected to the Homegroup and each share on the Mediaserver was shared to all homegroup users.

However that all changed recently when I read that you can switch to using username and password authentication in Advanced Networking Options which apparently is a lot faster (although I have't noticed a difference).

My Question then after much messing around:

What's the best way to setup network shares with authentication on a home network? I need to make sure that my sons accounts have only read only access to the server so they don't accidentally delete any photos or videos.