What kind of proof do I need to prove they haven't paid rent or is the burden of proof on them to prove they have paid?

Have you tried offering to write off the rent owed, if they move out right away? A negotiated surrender, on compromised terms, will be easier and...

Is my landlord right?

You really should reorient your thinking. From your question, it seems clear that you frequently pay late. Many tenants due that, confusing the...

Is this lease agreement valid since only one of the owner has signed the lease agreement?

If you are trying to find a way to invalidate the lease after purchasing the property, that horse won't fly.

It's not clear what you mean. If landlord made you a renewal proposal that you did not reply to, they can withdraw it. But if your lease contains a...

Is it a common practice to sell a business and simply transfer the lease to a new owner or do I need a certain clause for this?

It is a common practice, commonly handled badly. There are many issues. One big one is that unless your business will work in any location, much of...

Can they give a notice to vacate without a reason why? Do they have to give another notice since they took a payment for Jan.?

Duplicate posting. No, landlord does not have to give a reason for ending the lease. And your parents know the circumstances. Landlord legally...

Can they give a notice to vacate without a reason why? Do they have to give another notice since they took a payment for Jan.?

Your parent's landlord gave them more time to move out than is required by law. After your parents decided not to purchase the property. Moving...

Tenant's friend occupying the illegal basement room, any issues going forward?

Extend escrow. Make this the seller's problem. Advise seller and agent's broker of record that you will seek damages for their failure to disclose...

How do I get rid of this tenant???

If you rented out rooms without landlord permission, now is the time to come clean about it. Immediately let them know of the situation. If you had...

How long is reasonable to be in escrow?

Very possibly. It is advisable to have contracts reviewed by legal counsel before you sign them. You might want to do that now. You might also want...