It depends on the perspective of the speaker.
I would say that "control over" implies a much more domineering kind of "control" while "control of" just indicates some type of "control".
For example, I might write "The dictator took control over the rebelling population" as well as "The young leader took control of the confusing situation".
Dave, usually yes, but tener (and, as people have pointed out, compounds of tener) does not. There may be others but the ones I know have .....go as an irregular first person singular (eg tengo, pongo, digo, hago... from tener, poner, decir, hacer...). They seem not to to follow the usual rule. eg "puso" (no accent) is "he put". Similarly with first person, tuve, puse, etc - no accent.
Wouldn't you have recognized that the word was not present tense, and then looked it up? Are you in the past tense skill? Sometimes Duo gets words from other skills. It has happened to me before. It's irregular past tense, for sure. I use world Ref as my 'old faithful' when translating. http://www.wordreference.com/conj/ESverbs.aspx?v=obtuvo