Thanks Exige for the reply. I just want to start off by saying that you are killing it as well with your high income, maxing tax sheltered space + taxable and of course the valuable asset (the home). Sounds like you are on your way to FIRE. It's hard to go wrong with any decision you make.
With that said, here is how my mind thinks:
First I want to clarify that I prefer 30 year loans over 15 when starting out , not when I am halfway through a mortgage that is very affordable ($1700 @ 160k income), especially when rent will being in $2200. I am also a proponent of buy and hold and I like to make decisions with the long game in mind.
Let's play this out. Now, I have no clue what your taxes and insurance costs are, but i'm just gonna throw a number out there that it is $200 of the $880 PITI you mentioned. Also, I am making gross oversimplifications (no vacancy, rent increase, repairs, etc. but all of those factors would apply to both scenarios so they cancel each other out for this purpose).
The payoff amount for the 15 year loan with 7 years left is 142K plus tax+insurance for the remainder of the 22 years (58K) is roughly 195k
The payoff amount for the 30 year loan with 29 years left (tax+insurance already included) is over 306K+
Total rent collected over 29 years for the 15 year note will be 570K
Total rent collected over 29 years for the 30 year note will be 459K
Total profit for 15 year loan over the 29 years will be 375k profit + value of house
total profit for 30 year loan over 29 years will be 153k profit + value of house- the cost and time of refi
Obviously after the 29 years, both houses are paid off and they will be equal moving forward. But I see a 220K profit difference between keeping the 15 year loan and refinancing to the 30 year. Not the mention, being mortgage free after 7 years. Now life is much more complicated and there are a million variables, but if all variables stay the same, this is the cost. With the 30 year, you gain a little bit of flexibility, but I don't see how or why you would need the flexibility with a high income and positive cash flow.
Now, if you plan to put every penny of the 30 & 15 year mortgage difference (1700 - 880 = 820) into the market religiously, then I can see that being better, but I don't sense that from your replies.
Finally, the reason I wouldn't rent out a 400k+ house for $2200 is because alternatively, I would sale and take the tax free proceeds and put it in taxable. Sounds like you would clear 250K. 250K in a taxable over 29 years at a reasonable 5% is over $1,000,000. That is without lifting a finger.
Sorry for the long post and I hope the #s make sense. Like I said, you are doing great and you will be fine with any decision you choose to make. Best of luck!