In the first place, your forms are certainly correct, although they are lacking accents:
1 pl. impf. indic. act. ἐπηρωτῶμεν, 2 pl. impf. indic. act. ἐπηρωτὰτε
I've never thought to use a parsing tool at all. What I would consult if I felt insecure
about these particular forms is the paradigms in Smyth's grammar; I would expect
the forms for ἐπερωτάω to follow strictly the paradigm of alpha-contract verbs.
Why Perseus doesn't work for these forms I don't know, unless it's that these forms simply do not
appear in any of the texts in the Perseus corpus -- but I don't know whether the parsing tool is
supposed to fit all regular verbs or not.
Another resource for verb forms you might like to know about is Kalos software at:http://www.kalos-software.com/
It has downloadable programs for Windows and a .jar platform-independent one that will do
verb analysis and produce charts. The most recent version is kalos 4.4, released in January
of 2011. Kalos will do a number of different things, including definitions in English, French,
For irregular verbs, I would always check the initial section of LSJ entries for verbs, where all forms that are unpredictable are listed.