Enabling Cert-Based-Auth -- Will Word, and Webmail Break?

Exchange Hybrid mode

Need to enable certificate based authentication for mobile devices for mailboxes moved to the cloud.

Does enabling cert-based-auth make certs required for Word, Excel, etc.?

Do end user browsers then require the cert for webmail?

We have employees who work at client sites, on whatever PC they walk up to. We do not own, or control them. Therefore, these employees only have access to webmail.

Does enabling CBA require the browser to have the trusted root cert?

I'm thinking not, but I can't find the answer in any docs.

Thanks,

LT.Son