Then there's what seems to be a endless supply of properties that have yet to hit the market.

If you can't do all of those three things well, BRRRR will not give you the anticipated results of endless growth with none of your own money in the game.BRRRR allows broke investors to get into a lot of debt quickly. 

For instance if the comps were really uncertain, the neighborhood is particularly risky, if the project is a long distance from me and therefore more difficult to manage, and an endless number of other factors.

The options are endless.

If you have endless amounts of cash then by all means go for it.

Do you think I should grab another credit card (the offers are endless and I get great rates with my credit) or maybe grab a HELOC?

They really want to help but the bureaucracy maze is trying.

The options are endless to length of lease, if shorter than 12, will allow clean repair time but all crews are running at max because of that... 

Unfortunately, the rationale and the items on this list are endless, and putting this in a post such as this is a non-starter for me.

The reasons are endless.