Can I be sued for using an actor / actress's physical likeness for a text-based story, even if I put up disclaimers?

Yes, you can be sued.

The actresses have a "right of publicity" - in other words, they have certain rights to choose how and where their likenesses are used. Whether you provide a disclaimer or not probably doesn't matter too much here (you wouldn't expect to be able to put Oprah's face on a box of cookies and get a get-out-of-a-lawsuit pass because the box was labeled "Oprah Winfrey is in no way affiliated with Nesbixco", would you?).

Whether you will lose or win depends many factors, including the so-called "fair use doctrine." Before you take any chances, I'd recommend you try to get a release from the actors (have a lawyer draw one up for you). That's going to tell you pretty quickly if the actresses are open to having their visages on your site, or are ready to sic their attorneys on you at the drop of a hat.

Good luck - please don't take unnecessary risks - an hour of attorney time now may save you thousands later.

You'd be infringing on the actresses exclusive state law "publicity" right to exploit their own names, likenesses, voices, sigatures, etc. for profit, you may be violating the privacy rights of these actesses to be cast in a "false light" since their prior work was not affiliated with this new web series, and on top of that, you may be infringing the copyrights, if you use "repurposed" clips from films and TV shows, of the rightsholders (studios and networks) of those shows.

That's a lot of rights to trample on. I strongly suggest retaining an IP lawyer to run your plans by before you undertake the webisodes you're describing.

Disclaimer: Please note that this answer does not constitute legal advice, and should not be relied on, since each state has different laws, each situation is fact specific, and it is impossible to evaluate a legal problem without a comprehensive consultation and review of all the facts and documents at issue. This answer does not create an attorney-client relationship.