The strata roll must contain names and addresses for the owners. Note the address does not have to be where they live, it is an address for the purpose of service of strata correspondence etc. So if you were not given the addresses you should ask for them. Email addresses and phone numbers are not recorded in the strata roll.
The person/entity who can vote is the person recorded in the strata roll, i.e. the owner. An owner can give another person their proxy for the purposes of voting, and they can also nominate another person to be a member of the EC. So there is no issue with an owner giving his wife a proxy to vote at an AGM, or nominating her to be an EC member. It wouldn’t matter if they were married or not, so if the proper procedures were followed there is nothing wrong with her being on the EC and being Treasurer.
In terms of signing off on contracts, again provided she had the delegated power to do that, then there is no issue. You could ask to see the records of any decision giving her the authority to do that on behalf of the EC/OC.