Hi, as you can see from my profile, I have a lot of experience with Chrome extensions.
I watched both of your videos twice, and I understood everything you need to be done.
Regarding license protection, it can be done, but unfortunately it can never be 100% safe, and everyone having enough knowledge and time can break it (just like any other software, there is pirated version of each popular software).
Also, I can't do this for the money you proposed, I have experience with Chrome Extensions, and this takes at least 7 days to make everything work and get it tested. You can always get it cheaper from Indian developers, but I can guarantee with my 5.00 average review that everything will work as it should. And I know that similar extensions are sold for more than $2000..
I hope we will have a fruitful cooperation.
Regards, Stefan