[Antennas] inverted L

[RB]

I feel compelled to leap in here and demonstrate my ignorance.  

I've heard that the inverted L is essentially a form of top loaded vertical.  Is that true?

Assuming it is, will one designed for 160 also work on freqs above that band, with a tuner?  

Is the optimal configuration a tuner at the base of the inverted L?  

Will it work if the inverted L is fed with with coax, with a tuner in the shack?