> 1) If I'm given a 7% semi-annual nominal rate, does that mean the annual nominal rate is simply 14%?
No. 7% semi-annual is 3.5% every six months. So annual rate is $1.035^2 - 1$.
> 2) Continuing with the above, if my annual nominal rate is 14%, is my annual effective rate also 14% if there is no compounding?
Yes it's 14%.
> 3) If I'm given a nominal rate of interest of 8% a year convertible semi-annually, what is the annual effective rate? Is the answer to this: $(1 + .08/2)^2 = 1.0816$ --> so, effective annual rate is 8.16%?
Yes.
> Why do actuaries use the term "convertible" instead of "compounded"?
Beats me.