If they are occupying a POH then you can give them that as well.Beyond eyes and ears, they need to read submeters and report those back, assist coordinating repairs for infrastructure, tree trimming, etc.For special items like selling a home they can field phone calls from buyers, get the paperwork going, and put out bandit signs, etc.  

Not sure if that would work for the location or not and might require adding a fence, trees or something to make it more desirable.    

Ways to decrease tree save area?

Rates in our area vary from $85 to $135 per clean for a 1 bedroom with 1 bathroom, it depends on if there are additional services they are providing, such as: restocking supplies (toilet paper, paper towels, tea, and cleaning supplies, etc.), providing a small gift basket with a hand written note, etc.  

If so, your property coverage is limited to these causes of loss: FireLightningWindstorm or Hail (USLI often limits this coverage to a submitted amount on the policy, not policy limit)ExplosionSmokeVandalismAircraft or Vehicle CollisionRiot or Civil CommotionSinkhole CollapseVolcanic ActivityIf nothing else, be aware of the following, but I would recommend getting a more broad coverage from a competing insurance company for no additional charge that would include policy limits for the above windstorm or hail, and the following causes of loss: Burglary/Break-in damageFalling Objects (like tree limbs)Weight of Ice and SnowFreezing of Plumbing*Accidental Water Damage (think of a leaky roof that is causing water damage into your property leading rotting wood and or mold)Artificially Generated ElectricityMy Best,Ryan Leavitt

this house also has been that seem to be trees literally cut down the middle and placed As support beams.

The roof,windows,heating and air, water and sewer going to the main street, trees to close to sidewalks and the foundation, etc.The muni might also require on a vacant gut reno to put in sprinkler systems which can raise the cost up even further.300,000 is a very low yield for upside with all of that.

In the front yard there are several large oak trees and due to the shade the grass is very sparse.

You will not be risking offending the seller (and some sellers cannot see the forest for the trees and will be offended at any lower offer) and like Eric said, if someone else want's to pay more for it, let them.

Structural - tree fell on house; house is being flooded with rainwater.4.