Keep the letter unopened as evidence or keep the receipt as evidence that you followed the law.As far as the threats of litigation, I would not tell him "I will see you in court".

In this case both property owners need to consent to have the tree removed and becomes a civil matter.

It’ll vary by state, but in our state California Civil Code Section 1950.5 specifies for what purposes a landlord can make deductions from a tenant’s security deposit, including:“The cleaning of the premises upon termination of the tenancy necessary to return the unit to the same level of cleanliness it was in at the inception of the tenancy.”So ultimately it depends on how clean the unit was at the beginning of the tenancy, and how clean (or dirty) the tenant left it at the end of the tenancy. 

The Service Member's Civil Relief Act language only refers to terminating the lease.

Even then, I would have an attorney draw up a comprehensive partnership agreement so that issues like those described above are dealt with quickly without protracted and expensive litigation. 

Seek out Civil Engineers with landscape architects on their staff or develop a relationship with an L.A. well versed in local codes. 

If he ignores, I will probably be forced to file a civil suit.

Anyone have recommendations for a NJ litigation attorney that’s familiar with condo law and resonably priced?

Current as-built drawings, plans & specificationsDescriptions of buildings, physical aspects and systemsSite Plan (with dimensions and identifying tenants and vacant locationsPhase I and if applicable Phase II environmental site assessmentProperty Condition ReportStatus of ADA compliance (including ADA plans)Warranties (HVAC, roof, insulated glass, etc.)Existing exterior, interior, and aerial photographs of PropertyFloor plans with tenant location (CADD/PDF files)Any and all Leases and Tenant correspondenceAny and all Service ContractsGeneral Ledger for the past 3 yearsThree year history of delinquency and bad debtMost recent detailed billing statement for all TenantsTenant ledgers for previous calendar year & YTDCertified Updated Rent Roll and Certified A/R ScheduleList of security deposits and prepaid rentLeasing update (pending deals, LOIs, renewals, lease-up projections)Future Tenant improvements and leasing commission obligationsThree year history of tenant improvements and leasing commissionsCurrent year detailed operating budgetYTD budget vs. actual analysis for current year & 2 prior yearsThree years of operating statements (revenues & expense) historyCapital items/budget forecast (3-year projection)Three year history of capital expendituresProperty Tax bill for current year and previous 3 yearsCurrent Insurance CoverageThree year history of insurance claims and incidentsTenant’s sales volumes for at least 3 yearsThree year occupancy historyExisting appraisal report(s)Confirmation of ZoningCertificate of occupancy/use permitsStatus of pending litigation and/or threatened condemnationMost recent title insurance policyMost recent as-built surveyCAM Reconciliation for prior 3 years

I imagine she'd be able to easily litigate against you and would likely win.