-Renovating would result in a $250 rent increase for that unit.Any advice on how to prevent legal trouble and interpersonal conflict in this situation would be greatly appreciated.Last year I bought the triplex next door to this one, I didn’t renew any of the tenants, and then renovated all three units.

@Frances Elliott - we have a lot of 5+ year tenants and I do see a correaltion between job stability and behaviour, but its not a hard connection.

A lot of these folks may eventually become building inspectors due to their depth of knowledge in the technical systems, and you can imagine this would be useful knowledge for any investor to have.if they are inclined towards numbers, or the backend of the RE systems, then finance, accounting, economics, or even management could be a solid plan. if they are inclined more towards creativity or want to get into the development side of RE, then something in design, architecture, or engineering, could be a very fulfilling.If they have strong interpersonal skills, and are more self motivated and self driven, then something on the sales side may be a good choice; RE agent, finance brokers, property manager, or a customer-facing role they could do very well in.

You are going to vary how you conduct business depending on where you are delivering services and to whom you are providing them.The purpose of leaving a few basic items, such as a roll of TP or cleaning supplies, for a new tenant is not about trying to influence or change personal behaviour as you appear to believe, but about relationship management, marketing (referrals) and customer retention as @Karen P. and others have identified.Perhaps there is no value in providing any incidentals or welcome gift to new tenants in your market(s), but you shouldn't be too absolute in the conviction that your experience is a global truth.As I mentioned before, just because someone conducts business differently than you, or in a manner with which you disagree, it does not automatically follow that their "real world experience" is any less than yours.  

However for me I have the advantage of not being effected by this type of tenant behaviour.

PadSplit does all the marketing, screening, charging late fees, collecting rent, and dealing with tenants when it comes to interpersonal disputes.

Nothing harsh about enforcing rules in correcting bad behaviour as you point out. 

Some downsides I have in mind: harder to find properties with a good ratio of bathrooms to bedrooms, more expensive to buy a large property upfront, higher monthly maintenance costs (I would probably pay for utilities and communal furnishings), and interpersonal conflicts between the residents. 

The hard part is raising investment capitol here, the banks are either currently involved in some sort of unfavourable behaviour or have been caught in doing so and are so strapped with sanctions or cumbersome rules that they cannot easily move forward as one would be accustomed to within the US development banking structure.   

Real Estate, finances, interpersonal skills & handy maintenance skills are all in my wheelhouse so it's not hard for me.