Ancillary relief

I am the respondent in a divorce application. My wife is divorcing me for unreasonable behaviour. The application was filed in July 2010. The short version is:
mediation in october 2010. Shared residence agreed. She stopped the contact 6 weeks into agreement stating I could see the children 2 nights a week and if i didnt like it i would have to take her to court. Kids wanted to see us both equally. She refused to listen. Took her to court. Shared residence was ordered in August 2011( 9 months later, me having kids 47% of the year )
Asked her about splitting of benefits (in sept 2011 in solicitors letter on her return to this country from her 6 week holiday with the kids in Australia)to enable me to give children a better of standard of living (her net income is approx £700pw with council rent of £400 a month, mine net income is £240pw, with private rent of £750 a month). Eldest son is disabled and in receipt of high rate DLA and high rate mobility. She refused. I have now run up debts totalling about £15K in that time just trying to maintain a standard of living for my children in their home with me (additional food, clothing, utilities, housing, transport, toiletries, cleaning materials, extra curricular activities, equipment, phone calls bedding/linen, stationery, reading materials, toys, school stuff etc). I am filling out my forms as we speak and I have a date for a first hearing on 21st August.
My questions are these:
1. Can I make an application for spousal maintenence being the respondent?
2. Can i apply for maintenence pending suit and subsequently periodic payments?
3. Can i ask the court to back date the maintenence to august 2011? alot of my debt has accrued since the shared res order started, and attempts were made in sept to rectify finances, and at various mediation sessions, but she has refused to get in to any discussions about finance, even though the children are at a distinct disadvantage when they live with me, due to the large disparity in incomes.
My solicitor seems to think that because i am the respondent, i cannot ask for the maintenence to be back dated. Can anybady shed any light on this matter for me?

In principle, there is no reason why a respondent cannot claim spousal maintenance or maintenance pending suit. Whether the claim would succeed is another issue of course.
As to backdating, I''m inclined to think that your solicitor is right.
A Petitioner can make a claim for MPS or spousal maintenance in the Petition.
You, being the respondent, can''t claim either in the petition. You would have to lodge form A and make your claim that way.
I do not think that maintenance payments can be made in respect of any period which pre-dates the application. If this is what your solicitor is saying, I think he is correct.
LMM