When there is no physical mouse the cursor might not be visible. The iOS version has nothing to do with it - the same is true about the desktop Viewer, only in desktop Viewer you see the local cursor by default so that behavior is not immediately evident.
But this is a bug and we have already added it to our bugfix queue. We will fix it in one of the upcoming updates.
Direct connection is always better than ID connection, by definition. It is the simplest way to connect from local to remote, and if you still have serious performance issues even when using direct connection, you should check your network and router.
It should be noted, however, that in the upcoming version 6.9 we implemented some significant improvements to connection speed/performance. Version 6.9 beta will be made available on the site in a few days.