Hi BryanFRitt, thanks for your detailed report of your test of RC2!
It already helped me improving the score/tape upload error handling!
'yes' 'no' 'no, quit nagging me'
default should be 'no' (aka don't do it, but still nag next time)
Not sure about this one ... do you mean the "upload tapes to server" dialog at the very first start of RC2?
Well, R'n'D only supports "yes/no" or "confirm" dialogs. And there's no default -- "Return" is "yes", "Escape" is "no".
1st time trying to submit scores, it ends with this error...
`cat ./stderr.txt` shows
[WARN] wrong size (5) of chunk 'INFO' in tape file '/home/bryan/.rocksndiamonds/tapes/classic_boulderdash/048.tape'
[FATAL] cannot upload score tape to score server
[FATAL] aborting
Very strange! Any more info in "stdout.txt"?
At least, the "[WARN]" warning message about that tape file should not have caused this. Nevertheless, being unable to upload a score tape should not bring R'n'D to a fatal halt. I've fixed this, so it now shows a message dialog in such cases and continues.
should only submit scores that have been changed since they've been uploaded. (does it?, didn't test)
Offering to upload score tapes at program start happens only once; when done, it won't be offered again, and once the upload was successful, it won't be available anymore from the setup menu. Any further uploads will be done after a level was successfully solved then.
"- uploading score tape to score server - uploaded."
This looks like at least one score tape was successfully uploaded to the server (and I can indeed see a lot of successful uploads on the score server for a user "bryan" between 2021-10-08 and 2021-10-10). So I really wonder what might have caused that fatal error.

(I also cannot see any error messages on the server side.)
should this be hi score(s) AND tape(s)? are these verified as successful attempts?
After solving a level, score and tape is submitted, while initially only tapes are submitted (as there is no link between local tapes and score entries, unfortunately). All scores and tapes are verified on the score server.
the full screen / un full screen shortcut doesn't work while tapes are being submitted.
That's right -- during tape upload, no events are processed.
got a bunch of
[WARN] cannot read level '.. .level' -- using empty level
That's expected behaviour for all level sets with missing levels (like many sets from the EMC collection).
[WARN] cannot read level './levels/Tutorials/rnd_tutorial_niko_boehm/040.level' -- using empty level
This is strange, as this level set *has* a level 040. Is this file missing in this level set's directory, maybe?
[WARN] cannot write setup file '/home/bryan/.rocksndiamonds/levelsetup/rnd_tutorial_niko_boehm/levelsetup.conf'
I have no idea why this warning message was issued.
It didn't keep the last level played from the older version
Usually it does -- I assume this was due to the fallback to the first valid level set after the "fatal error" (which is "Niko Böhm's Tutorial" in many cases).
As failed uploads are handled better now, this should not happen again.
ALL LEVELS ARE ALL 100% DIRT 
exited
started again...
it looks like it's resubmitting everything again
looks like submitting again ends the same way as it did last time
ALL LEVELS ARE STILL 100% DIRT
exiting and restarting, this time selecting 'No' to (re)submitting, now the levels are back, and it's not prompting me to resubmit at startup
Again, very strage -- was this *after* restarting R'n'D after the "fatal error" (which should end the program)?
I hope this will also not happen anymore now.
looks like the number reported as submitted is way lower than the number of tapes I have
Does this mean that you managed to successfully finish the uploading process somwhow?
Again, I wonder what might have caused that fatal error, as many tapes seem to be uploaded.
looks like Hall of Fame has times only, what happened to scores?, ok... maybe it was just those levels?
Some level sets (mainly Supaplex) do not have scores at all -- these are not "faked" for the Hall of Fame anymore in 4.3.0.0. So you now have level sets with scores, and level sets with times (where lower times are better).
Future versions of R'n'D may contain a score details page which also shows the time for entries which have a score.
is there any way to view other's tapes?
Not yet.

(In fact, I'm planning to add this feature for one of the next versions.)
I noticed for some there are several of a persons hi scores listed, perhaps it should only show the best for each player
BD2K3, level 42, has like 18 high scores for 'BRYAN' (EDIT: does it only show multiple ones for the current player?)
It only shows the best score for each player for scores on the server, but it will always show all scores for your local players. Maybe I should add an option in the setup menu to also only show the best local players scores.
is there a way to turn off/on just the hall of fame music?
No.
it would be nice if I could easily see which levels have been beaten by others, but not by me (new color scheme?) (also I've beaten that no one else has, levels that I and at least one other have beaten, levels that no one has beaten; 2^2=4; 10^10=100 binary)
Yes, this could be interesting! Any suggestion how this could look like in the game?
what happens to these scores and new scores, if I change my name?, or if I've changed my name in an earlier version? case insensitive?
what about two or more people having the same name?
All existing tapes are uploaded with your current player name (as the tape does not contain the player name, unfortunately). All new tapes are uploaded also with your current player name. If you change your name locally in the game (and you are not offline), it will also be changed on the server, for all players accessing the score server. (If you were offline when you changed your player name, just change it again when your back online and it will also be changed on the server this time.)
If somebody else should have chosen the same name as you have, their name won't be changed (and vice versa), as every player also has an anonymous, but unique ID on the server.