Need Help With Floor Prep

[technoz]

I am in the process of diamond grinding the floor and I have a low spot near garage door, and door seems to have a high spot in the middle allowing water to seep in. Any idea on best way to correct this?

Also I tried angle grinding the garage wall with small cup wheel and it leaves circular marks, not sure why its not smooth.

What can I use over the spalled areas?

I was going to use elitecrete epoxy until I found out the price, I am leaning towards using legacy for my 3 1/2 car garage.

 

[LegacyIndustrial]

Swirls: Try holding the grinder more flat.
Spalling: Our HD110 or HD105 epoxy repair patches can be mixed with less sand to make a slurry. LINK: http://legacyindustrial.net/cart/concrete-repair-c-1.html
Pull the slurry over the spalling, trowel tight. Grind smooth.
Door: Get a threshold from us, saves the trouble of creating a transition cut under the door, seals out varmints, etc... LINK: http://legacyindustrial.net/cart/garage-thresholds-c-47.html