It is also going to take greater quantity of offers and efforts to culminate a deal.

If there is so much money invested in DST's, can one reliably say that sufficient number of investors are profiting?

The way to avoid this is to have sufficient reserves.  

If you can pay less than rent, and if you have sufficient reserves, that's the way to go. 

Lastly a Heloc will "Never" act as an asset or PITI reserve so if you fail to have sufficient funds required in reserves (Cash) then your will not buy multiple investment rentals.

I’m just joking around mate hehe  I figured as much but I think I may just not be sufficiently accustomed to Aussie humor lol

2) PS specific home - We looked at a few and were intrigued by one that is a 3/2 (plus self sufficient ADU, former garage) with a nice pool, yard but 2/2 on city records.

You should be able to find some good options on here so long as appraisal is sufficient and DSCR min is met 

When I do my own units, should I charge a really low price to my own property to make it self sufficient as it would then cover its own expenses, or should I charge the regular full price for cleaning and pay myself the entire cost for cleaning to boost my income?

Your primary insurance policy with $300,000 in liability coverage should be sufficient in 99.999% of all lawsuits.5.