When I first started counting I used red-7. It was a less overwhelming way to cut my counting teeth. After a little, I started to realize deck estimation didn't seem as daunting as it originally did. I got used to seeing the discards and could usually tell where we were in the shoe. I decided to switch to a balanced count because deck estimation no longer intimidated me and the extra accuracy seemed worth it.

I can answer a few of your questions:

-I think I will switch to R7 due to accuracy and ease
It is much easier! I think it's a wonderful count for someone who plays recreationally, would like to count, but would not like to invest a lot into learning how to count. There might be some more accuracy on your part at first due to it being easier, but the count itself can be inaccurate. It relies on the red sevens to be evenly distributed throughout the shoe. It seemed antithetical to counting to me. We use counting to determine the uneven distribution of cards, but red-7 relies on the red 7's to not be affected in their location for the count to work properly.

-How do I wong in with R7?
Watch a table and back count it. When it gets to the pivot, or a positive count that you've determined as your starting point, sit down and start playing.

-Is R7 going to attract more heat due to its weaker power, in the sense where maybe I have too spread to aggressively or something idk? Is it possible to be a R7 ninja? 70-80% of Hilo win rate in shoe games realistic as published?
You will have to spread more with red-7 than you would with a more powerful count. This might get you heat. When they evaluate your play, they may determine you're betting into negative counts (when the red-7's are more distributed to the beginning of the shoe) and feel you're less of a threat. For the second part, I don't recall the EV of red-7 vs. hi-lo.