If it's not an ironclad legal ROW, you are taking a significant risk. 

When existing tenants are on month to month rental agreements then you can proceed with legal notice of intended changes.

Even the lowest priced house still needs to offer any future resident safety and this area can lead to various very undesirable legal liabilities for the owner/seller.

If you are doing these for legal reasons, quote three sources.

I don't think ethically legally they can "price you out". 

If there is any legal existing easement or right of way they will have it on file and be able to show it to you on a map.

New update on the BH&J Rent vs Buy Index. https://business.fau.edu/departments/finance/real-estate-initiative/bhj-buy-vs-rent-index/bhj-summary/Interesting to note that most major markets have officially crossed over, where renting your residence and reinvesting what you would've spent on a home makes more financial sense than buying.

Check with your local laws but simply give them proper, legal, notice that as of "xx" date, their new rental rate will be $xxx.

I’ll let someone familiar with New Jersey law answer your question about online only rent payments (it wouldn’t be legal in my state), but I did want to caution you against accepting a check as payment for the initial deposit.

(Even if your form has a space to list one, it’s not something that’s legally required.)It sounds like you’d also like to increase rent.