Of course it can... Host your server+insim app on a better server, and make sure you host them in the same place... Or the other solution would be: Add delays between each button that's been sent, to avoid too high(not in general ofc, because the insim doesn't send much buttons at all, but in your case) connection usage.
As for if you are asking if someone can fix this for you, then don't look at me.
The code is just not structured(wonder if i got the right word here), but overall the coding itself, minding the small amount of buttons needed, is alright. After all I don't think that there is a big difference for the application's performance(if there is any difference at all), whether if you hold the code for bigger systems in classes or just type it freely(like is done in this insim app.).
The 2 main problems are that people, who try to change it will have a rough time, understanding how it works and when they need to change something they will need to go through lots of code, till they find the right place/s. That's all..
Well, you couldn't code anyway as you were always looking for people to do it for you and pass it on as your own work =) then thought you'd get them back by making the insim public lol
Kinda pathetic imo