You can offset deductions from passive activities of a PTP only against income or gain from passive activities of the same PTP. Likewise, you can offset credits from passive activities of a PTP only against the tax on the net passive income from the same PTP. This separate treatment rule also applies to a regulated investment company holding an interest in a PTP for the items attributable to that interest.
The average period of customer use of the property is 7 days or less. You figure the average period of customer use by dividing the total number of days in all rental periods by the number of rentals during the tax year. If the activity involves renting more than one class of property, multiply the average period of customer use of each class by a fraction. The numerator of the fraction is the gross rental income from that class of property and the denominator is the activity's total gross rental income. The activity's average period of customer use will equal the sum of the amounts for each class.
Passive income is definitely the goal and I think you hit it on the head with the point about upfront work. That actually coincides well with most physician careers. Work hard like a resident and spend like a resident to build up an investment portfolio right away while you are young and full of piss and vinegar. It then has time to grow and be there for you as you need or want to slow down because of aging or kids etc. Plant the seeds early and then live off the crops.