I don't think it will be a deal killer but the sellers will have to pay for treatment.

I have a background in wastewater treatment, I also have some experience in multi level business. 

Got the termite treatment done with some help, carpets removed, bathroom demoed, measured for windows and doors, working on putting a complete bid package together for Home Depot (If you spend more than $1500, you can request them to give you a bid price which is usually a bit cheaper). 

The most effective way is heat treatment but not something I can do in an apt.

When a specific infestation is discovered a more intense treatment will need to be done to bring it under control.

We didn't have contracts in place with many vendors, such as: lawn care, pest control (including white fly treatment), attorney, or irrigation. 

I can offer a list of services I would expect:Leasing fee covers:PricingMarketingMedia advertisingMember of Multiple Listing Service  and syndicated to numerous internet marketing toolsRealtor referral networkOn-call 24 hours including weekends and holidaysShowing, screening and negotiatingCredit reportsThorough background checksDocument preparationManagement Fee Covers:Move-in/move-out coordinationMove-out inspections with digital picturesEnforcement of lease termsTenant public relationsTimely rent collectionComputerized accounting and property management systemsFunds managed by a trust accountTimely disbursement of funds to ownerMonthly statements covering all activityCPA ready annual consolidated statementsScheduled property surveysMaintenanceProperty Repair Services24 hour on-call service for emergency repairs including weekends and holidaysRepair “help line” service at no costReputable maintenance personnelVolume pricing on supplies and servicesSpring A/C service and lawn treatment at owner’s optionUpdating, decorating and refurbishing if desiredInstallation of security devices (locks, etc) as required by law

When a property averages less than a 7 day rental period over the course of the tax year and qualifies as a non-rental activity, and non passive tax treatment, how is the rule about personal use affected?

The correct treatment would be that each of you would have been reporting a % of the activity of the property as tenants in common in the absence of any other ownership structure.  

But the two may not mix.An intermediate product like a TIC is a good thought but since what makes the tic qualify for 1031 treatment is that you take a deeded tenant in common interest in the real estate, it too must fall under the regs.