Confused with COE form

Hello there,

Me and my japanese wife started filling the COE form for spouse visa and we are kind of overwhelmed with all the info they ask.

Note that both are currently living and working in Europe and will apply from here, with the help of her father in Japan.
We are SUPER confused about "supporter in Japan" and "Guarantor" definitions tbh. Both of them will have to be my father in law? Or the Guarantor is my wife??

I'll divide by number as same as is in the form.

8) Home town/city.
Is this my current residence address?
I am applying with my italian passport, in Denmark, where I live and work as EU citizen, and will apply for the spouse visa in the Japanese Embassy here in Denmark.

25) Method of support to pay for expenses while in Japan.
If I bring savings from abroad as well, can I choose more than one option?
For example 100.000 yen SELF and 100.000 yen Guarantor is ok? What about "Supporter in Japan"?

26) Supporter (who's info I will in here? My wife or my father in law?)

27) Guarantor or contact in Japan. Again, is this my wife or my father in law?

28) Applicant, legal representative or the authorized representative, prescribed in Paragraph 2 of article 7-2.
Is this the person who will hand out the documents in Japan, my father in law?

And finally, below point 28, " I hereby declare that the statement given above is true… Signature of the applicant (representative) and date.
Does my father in law has to sign this part? So, not me?

I really apologize in advance, since maybe are some stupid questions, but we don't want to mess up the application. My wife's been looking up online for examples, mostly in japanese sites, and people seems to fill this COE form in very different ways, specially those points I ask here.

by neko1985