Hi Maksym,
You are very welcome!
1. Yes, but it also depends on the configuration you have on the Frontend search settings -> General panel: http://i.imgur.com/zkPCKmv.png
The flex layout with the automatic rows count is usually the best.
2. It looks like this might be a bug I haven’t noticed yet, for the custom field selectors. There is a max height set to automatically start the scroll, but it’s missing for the custom field selectors. I’ve noted this for fixing for the upcoming release, until then, you can try using this custom CSS as temporary solution:
[html]fieldset.asp_custom_f {
max-height: 220px;
overflow: auto;
}[/html]