Unprofessional home page - needs proofreading!

A bit strong. I think typo would be a little kinder. I do believe the site and that page are very professional in design and any typos are an oversight of the web designer or whoever updates the text. I actually like the site very much and fully respect whoever designs it.
 
You have a good eye though, yes. And many a native English speaker makes these mistakes.
 
For reference:
We cannot use it's to mean belonging to it. We need to remove the '. So that it just reads its..
And apart means separate from. So the correct sentence should read a part of..
 
Good find. Be honest though, the site is pretty good, yes?