Translation:She touches me a few times a second.
Yep, there is a general rule. aan is a separable prefix of the verb aanraken. It always goes at the end. However, when the verb is at the end, it will look like aanraken. Here are some examples:
"Zij raakt mij een paar keer per seconde aan."
"Ik wil het aanraken."
As you can see, if the verb is not last in the sentence, you have to separate it and put the prefix at the end.
Hope this helped!
A little correction: Your rule about position is just a rule of thumb with lots of exceptions. The real criterion is whether it's a finite verb form or not. Finite in this context means that the verb form changes with person and/or number.
The non-finite verb forms - the ones where the prefix is not separated - are the infinitive (aanraken) and the two participles (aanrakend, aangeraakt). A little complication is that for the extended infinitive with to (i.e. to touch rather than just touch) the word te is put between the prefix and the verb: aan te raken.
Contrived example of all non-finite forms of aanraken in non-final position, followed by a sentence with a finite form of aanraken:
"Het aanrakende en aangeraakte dier aan te raken is gevaarlijk. Dus raak ik het niet aan."
A preposition splitting a verb is of course pretty strange. In my native German we do it the same way (the German equivalent of to/te being zu), but spell the result as a single word rather than three. (Example: anfassen becomes anzufassen.) There are good reasons for both spellings, and neither is completely satisfactory.
Sadly you can't report it unless you've just gotten the question wrong. You'll just need to go through the lesson until you find it again if you want to report it.
Generally what I do if I have doubts that a translation is actually wrong, I'll generally report it then ask about it. Like I said before, if it isn't right they simply won't accept it, but that way you don't have to worry about going through and finding the exercise again.
Sorry there isn't a more convenient solution. :/
Not necessarily. Hit is sometimes used a bit more generally, and on the other hand if you touch someone several times per second the act of touching implicitly gets into literal 'hitting' territory anyway, just due to the speed. So I think it could be accepted as a free translation.