Total time spent throughout the year may be significant, depending on the number of properties and amount of activities, but year end is no more difficult than any other time period they're doing. 

(Usually you cannot use prior employer history until you have been at your new job for 6 to 12 months, depending on the underwriter to show that you are maintaining the same level of bonus/overtime/commission income that you had at your prior employer).

The proper answer is "it depends" I don't know anything about your case.I do prefer simple over unnecessary complexity.

Rates as low as 7.25, depending on credit score and LTV.

Airbnb rental arbitrage can work, but it depends.

Depending on the market you invest in, you may have enough to go all cash on the first deal and refinance to put money in the second deal. 

As far as timeframe, anywhere from 21-45 days depending on how quick a borrower gets their docs to underwriting, how long the appraisal takes, etc.

It depends on what exactly you are referring to with gap funding.

Days on market are around 80 days on average, depending on the area.

From the numbers perspective it seems like it can pencil out depending on the rehab budget.