There are many accepted forms and this one was missing, added.

No, impossible. It must be with either

"zajímat se o něco"="to be interested in something" -> "Zajímáš se o toho muže." where "toho muže" is the object in accusative and the omitted subject is "ty".

or

using "zajímat" as "Ten muž tě zajímá?" or more common "Zajímá tě ten muž?" where "ten muž" is the subject in nominative and "tě" is the object in accusative.

No, they have their own purpose in the sentence. Here the se is part of the verb "zajímat se". Did you read the Tips and notes?