Yes. There is a product called AppColl Tandem that allows for your client to have their own AppColl account (free of charge for AppColl PM Plus users). The Tandem account give them access to whatever data you wish.

See here for more information.
https://support.appcoll.com/general-information/tandem-account-overview

When a page is locked, it means someone else is currently accessing the page. This is done to prevent two people from simultaneously editing the same page. There is an option shown by the page lock text to send an email to the person using the page. This option sends an email that someone else is trying to access the page.

Yes, Invention Manager and Prosecution Manager integrate perfectly with one another. Integrating both products gives full view of all IP from start to finish.