Simple Tab using non proportional fonts (ASCII Tab) often uses the number of dashes on the string lines (which is a dashed line) to indicate the duration of the note. Other Tabs use the amount of space following the note as a guide. Some Tabs give no timing indication - if you don't know the song you can't play it.

My preference is as Mark's above, for music above Tab almost like a piano piece. As a teacher I use simple tab to indicate finger placement. Tails and such on the Tab add confusion for the non reader IMO - what you then have is a hybrid between Tab with its reading siplicity, and music with the terror associated with this bizarre sign language.

Hammer-ons slides bends etc can be shown with abbreviated written instruction above as you suggest.

Good luck

Stu