Thank you for your question. I look forward to working with you to provide you the information you are seeking for educational purposes only.
Under the MA Sanitary Code, property owners/landlords must keep all means of egress free from obstruction — that cannot be negotiated away. As for the removal of snow and ice, the Code provides that the landlord shall maintain all means of egress at all times in a safe, operable condition and shall keep all exterior stairways, fire escapes, egress balconies and bridges free of snow and ice. Again, those obligations cannot be negotiated away in a lease.
A landlord may require the tenant be responsible for snow and ice remove in a lease provision only where a dwelling has an independent means of egress, not shared with other occupants, and a written lease provides for same.
As far as charging the tenant for removal, as it is the landlord's non-delegable duty, you cannot charge for plowing, but you could adjust the rent accordingly when setting the rent to include the yearly plowing average costs into the rent without calling it specifically for plowing, which would be disallowed.
2) Because the landlord's duty is not negotiable, even if you agree to reduce rent to the tenant in exchange for the tenant plowing, you as landowner would ultimately be liable. You can agree to pay the tenant, by reduction of rent, for plowing and in your lease you can include a clause stating tenant agrees to plow in consideration for "$X" for each snow event requiring plowing. This is no different than you hiring a company to plow. This does not make the tenant liable to do so, but if they do it you are paying them by rent reduction.
3) If a tenant is agreeing to do yard maintenance and grass cutting, then it needs to be stated in the lease and you need to specifically state that there will be a reduction of $X per month in consideration for them performing those duties, but in any month they fail to perform them they will have to pay the full amount of rent due.
4) You would be better off stating that they agree to plow or mow and in the event they do not do so within 12 hour notice from the landlord, they will not be eligible for the $X reduction and have to pay the full rent as indicated in the lease.
5) MA law requires that tax escalator clauses be written in a certain form to be enforceable. In MA a tax escalator clause must contain three things:
1) A statement that you are obligated to pay only that portion of the increased property tax as your apartment
bears to the whole property being taxed. For example, if you live in a three unit building and the units are all the same size, you would be obligated to pay only one third of the increase for the whole building.
2) The exact percentage of any tax increase that you are obligated to pay.
3) A statement that if your landlord gets a tax refund, or tax abatement, you will receive a proportionate share of that reduction (less any lawyer's fees that the landlord paid in getting the reduction). For example, if the city sends your landlord a refund after she has already paid her taxes, you would be entitled to a proportionate reduction in rent. Here is a sample lease with an escalator clause: https://www.formsforrealestate.com/pdf_files/SINGLE_FAMILY_DWELLING_LEASE_SAMPLE.PDF