Keyboard shortcuts for items under "Edit" menu
You can call a menu item with type a key after displaying "Edit" menu. When you disable the meta key, "Alt-E a" calls "Select all".
Select *a*ll Clear *s*creen Clear *b*uffer
Or did you suggested about alt key combination, like "Alt+v"?
Tera Term
It would be nice to have keyboard shortcuts for some of the items under the Edit menu that today do not have shortcuts. These include "Select all", "Clear Screen", "CLear Buffer".