I agree with the others, but want to suggest that it if you have given Power of Attorney to someone in whom you do not have the utmost trust and confidence, you ought to consider revoking that power.
The fact that you worry about being tricked by him concerns me.
Do yourself a favor and retain counsel. Your 30 day notice is likely insufficient to terminate your roommate's tenancy, whether she be a licensee or invitee. You're probably going to have to start over, better to let an attorney look at what you have done and either continue or fix it accordingly.
Best of luck!
You need to provide more information. Was there a Will? How do your names appear in title? Is there any income generated by the house, and if so, do you share in that? Do you share the expenses?
Until it is signed by both parties, you had no agreement. You had, at best (putting aside an argument of "mistake"), an offer that was not accepted. Landlord has the right to change the offer as long as you had not both agreed on the original. You signing the first with knowledge of the second will not work.
The prior answers by attorneys Bianchi and Rothstein are good, but I wanted to point out something that might not be so "obvious" as someone who has represented local churches in similar evictions. It's bad press and you don't want to have the Church's name as claimant in an eviction -- especially where you say the issue is the people "doing less" and the fact that the church wants more income. The church should retain counsel to delicately try (nice letters) to get the people out without...