If i am not wrong, Google will not index those page URL since these page URL not generated on the page.

Thats correct, but its gonna be very easy for anyone to serp spam any popular website by just putting up backlinks all over the internet, if there issnt a canonical or a noindex tag, it will index for sure.
SH404sef is a good solution to fix this, as it redirects to the main (but there are a few bugs with your sef_ext files, making it hard to acheive proper URLs, and i dont think its gonna be fixed in next 2 years or so). Ideally, since there is an option for permalink check there shouldnt be any id, or if its an ID, (like fb initial reg) it should be ID only no username, and it shouldnt be a wildcard url kind of a thing.

Thanks for your input, i will lock into our issue tracker and see what we can do about this.

Hey usamam,

I already consult with our developer regarding this, it seems like currently that is no way to check this, the reason why it will show the profile alias with the user id by default is because it can support who want to display unicode aliases in the profile URL.

But like you said Sh404sef can achieve this based on our sef_ext file, so it can able to show the user alias without the user id.

Perhaps you can elaborate more details what is your current issue when you using Sh404sef on your site?

And what do you mean by 'making it hard to achieve proper URL'?