Does every cyber combat action represent loading a new attack program? Does have to have an attack program loaded for every attack they want to make per turn? Or is it just load an attack program: make as many attacks as they want till the end of the combat?

You just have to load the program once.

Loading the attack program into your comm is like strapping a sword to your belt;
it is there ready to be used when needed.

You don't even have to reload the program for a second combat.
It is still there at your hip, ready for any other takers.

Unloading the program from your comm would be like taking off the sword and packing it into your backpack;
you can still access it, but it takes a bit of time to get to it.

Basically, if a program is loaded its ready to be used, or in the case of some programs, its running autonomously.(IC, stealth, analyze to name a few) The program will stay that way until its unloaded to free up resources, or if its Crashed by an opponent.

Also, is it just me, or did the anniversary edition change the Crash attack option to use exploit instead of attack?