(b) One or more cotenant heirs of real property may acquire the interests of other cotenant heirs in the property by adverse possession under this section if, for a continuous, uninterrupted 10-year period immediately preceding the filing of the affidavits required by Subsection (c):(1) the possessing cotenant heir or heirs:(A) hold the property in peaceable and exclusive possession;(B) cultivate, use, or enjoy the property; and(C) pay all property taxes on the property not later than two years after the date the taxes become due; and(2) no other cotenant heir has:(A) contributed to the property's taxes or maintenance;(B) challenged a possessing cotenant heir's exclusive possession of the property;(C) asserted any other claim against a possessing cotenant heir in connection with the property, such as the right to rental payments from a possessing cotenant heir;(D) acted to preserve the cotenant heir's interest in the property by filing notice of the cotenant heir's claimed interest in the deed records of the county in which the property is located; or(E) entered into a written agreement with the possessing cotenant heir under which the possessing cotenant heir is allowed to possess the property but the other cotenant heir does not forfeit that heir's ownership interest.

@Clayton Hepler,The Whitaker area is coterminous with Census Tract 4850 in Allegheny County, PA The makes it easy to look the data and will help make an assertion as to the quality of tenant one should expect. 

I believe that there should be a balance of not getting to stressed out about it and taking assertive action to let them know I’m on to their slobbish ways and that action will follow if continued.

(This is your "I'm just the property manager landlord")Toby Flenderson: A completely ineffective person who cannot assert himself and if he eventually does he does it in a fit and it alienates him from others.

That is a great question for your property manager but generally just because you accept partial payment it does not mean you are giving up any of your rights as asserted in the lease(not a lawyer) .

Assert you are seeking knowledge, not a signed document to take to court.

Landlord shall not be liable for any damage or injury of or to the Tenant, Tenant's family, guests, invitees, agents or employees or to any person entering the Premises or the building of which the Premises are a part or to goods or equipment, or in the structure or equipment of the structure of which the Premises are a part, and Tenant hereby agrees to indemnify, defend and hold Landlord harmless from any and all claims or assertions of every kind and nature."

It's also where someone with some experience can assert his experience into the situation, despite the greener third party conduit. 

The manager needs to assert themselves and make the tenants acknowledge that they are to address any correspondence about the property to them and not you.The management especially wants to correct any mistakes you may have made last time by making the tenants aware that tardiness with rent will not be tolerated and will be swiftly dealt with legally.Any maintenance problem must be reported to the manager as soon as possible to prevent further damage.If they disagree with the manager they are free to leave so you can get a better tenant.

Learn To Persuade, Not Assert.