Random Lubuntu PCManFM questions/feedback

[isopropanol]

1.
In Lubuntu 18.04 I could RightClick - R to rename a file.
In Lubuntu 19.04 that does not work. Rename is still there, but it does not show an underline when you press Alt.
The Move to Trash "M" shows an underline. I'm not sure why Rename lost it's quick-key. R did not get remapped somewhere else, it just does nothing.
The about says PCManFM-Qt version 0.14.1

2.
I really would love some way to get a dark theme.
Everything I've read online says PCManFM does not use the QT theme or any other common theme. It uses it's own CSS.
But nothing has pointed me at where/how to modify that CSS.

3.
I don't think this is PCManFM related, but sometimes my Copy/Paste (the clipboard) gets hosed.
I originally thought it was just PCManFM, but now I think it's Lubuntu 19.04 in general.
I can still drag and drop to copy files around, but CTRL+C / CTRL+V pastes the last thing in the clipboard, but I can't overwrite something new into the clipboard.

[Dennis N]

These relate to Lubuntu 19.10. You should upgrade, as 19.04 is soon to be unsupported.
1 Press F2 to rename a file.
2 Can't help here.
3 Click entry in clipboard memory, then Ctrl+V, otherwise you paste the last copied text.