Hi morning,
I understand you are new to the forum. So, please note that you need to post GRE essays into "Writing Feedback" forum and also have a meaningful topic for the "Subject" when you open a new thread. They are forum rules and also they help you earn good feed backs for your essay.
Firstly, the letter, being from just a single owner in Central Plaza does not vouch for the opinions of other owners. Do all other owners agree with the suggestions made in the letter?
... better include suggestions also (in the place where I highlighted)
Also, can the decrease in the business of the shopkeepers solely be attributed to increase in skateboarding users ?
The author fails to mention what kind of shops he is talking about. Would a flower shop be really affected by increase in skateboarding?
.... this is a good argument, but I wish you took it to a different paragraph because this one deals with his failure to provide statistics. So in this para you better have the arguments that deal with statistics.