TI...aka Tenant Improvements...your future tenant may want to negotiate different terms for the move in, like a few months discounted rent(this could be on top of the above mentioned vacancy) while they build out the place, or some concession for the Tenant Improvements, if you  have an empty shell it could require extensive work to make it business ready for different types of business, think needing to add bathrooms for a gym(dozens of showers and toilets, lockers, etc) or adding a fully equipped commercial kitchen(walk in freezers, special fire suppression, a few extra sinks or drains) With apartments, I rarely have to do extensive build outs or concessions for tenants, even if I have full on renovation, it is almost always replace the old with same but new, ie tear out old kitchen put new kitchen in same place, same plumbing, just new cabinets, and flooring(if you are at all handy, you can do most of it yourself, or be able to estimate accuracy of bids easily).

My goal is to generate deals, wholesale the ones that don't fit my needs and cherry pick properties.Mailers are relatively inexpensive (4k or so for an aggressive campaign) but are they effective?

Cute updated decor, comfortable updated beds, well-equipped kitchen, etc are all always appreciated and noted in reviews.

I use Zoho CRM for my investing business since it's industry leading, completely customizable, and under constant development to stay ahead of the feature trends.For my agent business, kvCORE is an all-in-one CRM & Lead Generation platform provided for free by my brokerage.

If there's a big difference in size, number of occupants, or amenities (washer/dryer, dishwasher, etc.) then you may need to generate a formula that better reflects actual usage.3.

If not, why not just lead generate wholesale leads? 

Most good deals are found with months of follow up, off market lead generation, and relentless closing ability.

The homes for this next generation of buyers were never even built.

I think kitchens without the necessary equipment are a big issue.

Sure, some modern building methods are far superior to what was used in the past, but lots of building methods used today aren't nearly as robust as in prior generations (ask an experienced GC). ....Additionally, a new house is still in its "growing pains" phase, and a lot of serious problems can emerge in the first few years of ownership--e.g.; foundation/structural settling, improper water diversion systems creating rot, etc.