Organizing emails

I’ve just started using Runbox and have imported the emails from my GSuite account using IMAP during the night. Currently I have about 30k emails or so in Runbox. So I have some questions about organizing the emails:

  1. I find that moving around between the folders seems sluggish. If keeping the synchronization on, I find that the emails shown in a folder can be completely different from emails shown in that folder earlier. Or the folder will appear completely blank. I tried turning off synchronization, and it seemed to improve. But should I synchronize the email folders? And how can I best synchronize many emails in multiple folders? Do I really need to keep the folder open in the browser (so that the “Synchronizing X of Y emails” message is visible)? Isn’t this something that could be done in the background?
  2. When viewing folder containing many emails in unsynchronized mode, I find that emails are not listed according to received timestamp, but will vary in received timestamp (first newer emails, then older, then newer again etc.). Is this just how it is, or will this be corrected after a while?
  3. Why is there a “Toggle message read” functionality rather than a “Mark all messages read” functionality? If I have hundreds of emails where emails here and there are unread, I’d like for all of them to be unread. But I then have to select all the unread manually and set them read. Otherwise if I mark all emails and toggle the read state, the read emails will become unread and the unread will become read. I don’t see the logic in this functionality. I’d rather see that all messages are set to be read regardless of their prior state (read or unread).
  4. How can I select all emails in a folder, including those not visible on the screen? The “Check all” button only selects those visible, so I have to scroll down and click it again and again to select all.

Any response on this?