Cisco ASA upgrades for the uninitiated

Hey r/networking, I’m more traditionally a systems guy, so forgive me if this is a basic question.

I have a 5508-x running on 9.6(4)-34. I recently upgraded it from an older release of 9.6(4) due to a dos bug (not the 213 days one).

Anyway, to play it safe I stuck in the 9.6(4) family and just updated to the latest. However, in the interest of not letting the system get too far behind, I thought it might be time to research going to one of the latest builds, 9.8? 9.9? However, trying to read through Cisco’s website is kind of a pain for the uninitiated, I was wondering:

1. Is there a quick and easy place to find change notes for the mere mortals? (Example of something for SQL Server: https://sqlserverbuilds.blogspot.com/?m=1)

2. Anyone have any advice, should I go straight to the latest? We’re not doing much, we have a handful of IPsec tunnels, Remote access, normal firewall inspection, and only one open port for an external facing service. The only thing I could find that stood out to me was the addition of VTIs in one of the releases. 95% of my tunnels are IKEv1, but I’ve got one up to Azure that is ikev2.

3. What’s the general relationship with ASDM, AnyConnect and the ASA version? I see in the matrix that my particular version has shows to be compatible with ASDM 7.9+, does that really mean on up (to 7.12, etc), or just within the 7.9 family? Same with AnyConnect, have there been strict requirements that the version match the ASA software?