You are worried about the wrong things.
There is one thing that matters outdoors on a large screen - brightness.
This isn't home theater, you aren't inside with a properly setup home theater, you are outdoors with street lights, moonlight, and other uncontrollable lighting situations. You would be lucky to achieve a 500:1 contrast ratio, and sports don't demand the same high contrast that a good movie asks for.
But, what sports does like is lumens. More light on the screen is a key part of the experience.
Now, your projector isn't 1,200 lumens. On the day you bought it, the first few hours of use, in worst quality, uncalibrated mode, it may have been able to deliver 1,200 lumens... maybe. But, in typical usage mode after some lamp wear, you are more likely getting 600 lumens or less out of that projector. So, your image quality will be significantly impacted by this. Very significantly perhaps.
It comes down to some math, but a 16'x9' screen is 144 square feet. At 15 lumens per square foot, you would want a projector which can output at least 2,000 lumens, and preferably 3,000 lumens after calibration. That's not a terribly bright business class projector, but is a very bright home theater projector. Since most home theater projectors run on about a 8' width (110" diagonal) you are talking about a screen that is literally four times the size of the average home theater setup. So, you realistically need no less than four times the brightness of an average home theater projector.
Now, that bit said, actual clarity - image quality through resolution - will follow the standard rules of projection. That is, middle seating should be 1.5x the screen width. So, a 16' wide screen should have optimal seating at about 24' away from the screen. That is the same as sitting 12' from a 8' wide screen in your home theater.
Most projectors have a lens system which allows them to focus on a screen up to 300" in diagonal or so in size. So, focus should not be an issue at all.
At the end of the day, I WOULD get the material you are looking at. The price is right, and building a frame isn't that pricey and will give you very good results. You will have fun with this setup, but you may end up wishing for more lumens. You DO want white material that is not shiny! Shiny materials for screens don't properly diffuse the light which is what you want/need for a decent image and a grey screen, while it can slightly improve contrast, will also dull an image, which is not at all desirably for a large setup. Hence, I don't think you've seen a movie theater in your life which uses anything other than a white screen.
Should you really enjoy doing a large screen outdoor setup, then you may decide to get serious with it by mating a proper projector to the screen size, in which case I would look at this list:
Find Projectors By Feature
That list represents 1080p projectors with at least 4,000 lumens which are under $3,000 and have a HDMI input on them. Right now I would probably recommend this model:
Optoma Projectors: Optoma EH501 DLP projector
With 5,000 lumens, decent contrast, HDMI input... It will handle the screen size you have and leave room for calibration of colors so that you get the best image possible while still having a bright, punchy image on screen.