Any tips for analyzing properties. (1% & 50% rules)

[Evan Rumble]

As I am moving towards my first investment, I am currently trying to analyze as many properties as possible. assuming the property doesn't have any obvious red flags, I normally start with a quick check for the 1% rule and 50% rule, as cash flow is really what I am looking for in my investment. If it passes those, I will run a report on BP to further analyze.

1) Should I live and die by the 1%, in terms of deciding whether I should dive into deeper analysis on the property? If something is at 0.9% should I completely rule it out from having any cash flow potential? 

2) These rules seem very dependent on semi-accurate numbers (estimated rent; asking price - which is then dependent on things like estimated repair costs; etc.) Therefore, there are probably deals that could have been great, but I underestimated the rent / didn't consider negotiating a lower price (making the property fail the 1% rule). Is there any advice for improving my accuracy at predicting these important numbers? accurate rent estimation is one of my biggest issues/concerns. 

3) another set number I have a hard time estimating is expenses. Are there percentages I could use to estimate individual expenses, for when I want to get more precise than assuming 50% of rent will be expenses. (insurance, cap ex,  etc.) Obviously, property tax will be dependent on my location (east of Akron, OH), but will any of the other individual expenses be highly area dependent?

4) Lastly, is there anything else I should be adding into my initial analysis; before I visit the property, talk to contractors, etc? As of now, I first make sure there are no big red flags like the neighborhood, school districts, too much repair needed, etc; then I look for the 1% or 2% rule; the 50% rule; try to estimate repair costs/ARV (which is hard for me).

I would greatly apricate any feedback, and I apologize if any of this was hard to understand.