automator: shell script to change file permissions

What I want to do is recursively chmod the subfolders and files of a "root"-folder.

The way I know to do so is:

cd /root-folder
find . -type d -exec chmod 755 {} \;

That will chmod all subfolders from the root-folder to 755.
Next i want

find . -type f -exec chmod 644 {} \;

That will chmod all subfiles fromn the root-folder to 644

Unfortunately, find gives me a permission denied when I run this command from the command-line. When I just manualy chmod everything that works fine but is a bit to much work when it comes down to a tree of 5 subfolders and 120 files.

Waht basically hapens:
The user selects a bunch of folders.
Then they are copied to /Applications/RCT3.localised/Data/Styles/Themed

and then I need to chmod them just to be sure, as sometimes stuff break along the way if you don't

Hmm, you're quite right, it shouldn't.

Wondering what is causing the issue though...

Figured it out, my tester screwed up his file permissions, doh :/

I have a second question though.

Say that folder I'm trying to chmod contains some folders owned by me and some by someone else. Obviously you can only change the permissions on the ones you own, but how do you tell that to Automator?

as in
find . -type d -exec chmod 755 {} \; but only for files I own?

Last one:

Is there a way to remove the Cancel option from the Ask Confirmation Dialogue? I do want to inform the user halfway of what is going to happen next but not have them able to cancel the whole thing.