Getting online should be easier
The current login and getting permission is annoying. I just want to note the threshold to registration and trying should be almost zero at this stage - after fixing the UI (see previous issue). I know this may be a lot of work to get right - but it is your first user impression.
There are companies that put user experience first, and think technology later. I have a impression with Arvados it is the other way round - which is not a bad thing. But UI should be high on the list from now on.