I can speak to some of this stuff in my official capacity.
Re: Differences between RF8 and RF8 Horizon Hobby Edition, primarily the latter added a lot of content from Horizon brands that became available for the first time after Horizon Hobby began publishing RealFlight. Users who already owned RF8 could optionally purchase the HHE Add-On which would upgrade the earlier version to the Horizon Hobby Edition. You can find
more details here.
Re: Trim, whether RealFlight stores the values between sessions depends on whether the vehicle is stock content or a custom edit. You can never permanently modify stock content, so trim changes made during a session will be discarded when you exit. In contrast, if you're flying a custom variant (that includes EAs and AVs from the swap pages as well as any variants you have saved yourself using RealFlight's built-in aircraft editor or the Quick Edit feature), your trim changes will automatically be saved as part of that vehicle and will persist between sessions.
The radio gadget provides visual indicators for the current trim positions for each channel. Any trim that is not centered will be colored red to make it obvious. (
@Flapper got this backwards as far as when they are colored, but the principle is the same.
)
As
@Bill Stuntz said, starting with RF8 the controller was not part of the registration process.
Everything you interact with for RealFlight is part of Horizon Hobby now. That includes all the servers that the software talks to and these forums. So, rest assured your software is registered with HH, and online updates that you download come from us.
RF-X is the only exception, and a little bit of a gray area. HH did not acquire RF-X from KE. We do not own the source code or the rights to it in any way. However, as a courtesy, per agreement with KE we are providing registration, online update, and activation services for it.
When Horizon purchased RealFlight from Knife Edge, most of the team moved over to HH to continue working on RF. KE is still around. We're still friends with those people and see them socially sometimes. They're working on other things. They do not have their own forums, nor do any of them post here on ours.