I would put even less weight if a 'financial advisor' is doing other services such as taxes / insurance because he / she is looking to make money in anyway possible.I personally think if you want some financial advice, you should seek someone with the CFP(certified Financial Planner) designation. 

Intro:I have sent two certified letters to both neighbors notifying and requesting they trim their trees.

First, get certified funds at move ins. 

My question is, if they already signed a lease with the new amount stated, do I still need to notify them via certified mail?

You can offer to lend the seller money to stop the foreclosures. 7 or do a lease with an option to buy - making up the back payments that would be considered you advance lease payment.Always look at the property if you have intentions of bidding at the auction (this can be tricky because you need to do that with the owner's permission - do try to build a rapport with seller  - also look at the foreclosure suit to find out what the bank is looking for and if there is a second mortgage or other liens.At the court house steps when the auction take place you need to be well prepared with your certified funds but more importantly you need to know the fast sale value of the property - you don't want to pay retail.Get to know your competition - there will be professionals at the foreclosure auction looking to capture some serious equity.

Could I call myself a certified doctor?

We just notify them certified mail and provide MHA the request form, 3 comps and proof that the tenant was notified of the increase 60 days prior.

That requires you to be able to send them a certified letter or have a process server hand-deliver the notice. 

Should i send them a rent increase certified letter?

I did keep the EMD from the 2nd buyer -- I had to write a letter and drop it off at the title company because my agent didn't do it and I got a certified letter that they were going to release it back to the buyer if they didn't get written notice from me.