Hi,
On the first one: TinyMCE comes bundled with SilverStripe (it's the actual editor you see in the backend).
If you would like to modify the functionality of TinyMCE these links might help:
http://doc.silverstripe.com/doku.php?id=htmleditorconfig
http://silverstripe.org/general-questions/show/259503?start=0#post259582
http://ssbits.com/customising-the-wysywig-editor-in-v2-3-2-tinymce/
If you need a separate upload-field, you can simply add it with:
$fields->addFieldsToTab("Root.Content.Main", array(
new ImageField("myImage","My Image Field")
));
This will add the field below the editor.
On the second one: I don't exactly know; I have no experience with this.
But after reading this article: http://doc.silverstripe.com/doku.php?id=modules:external-authentication
I guess you have to get the username from the member-table.
Next digg into onBeforeWrite to learn how to automatically create a folder with their name on it
Then you have to figure out a way to link all ImageFields/FileFields automatically to the folder of the logged in-user - you might have to extend FileField and/or it's subclasses for that.
Please look into UncleCheese's ImageGallery-module to get a clue about automatically creating and opening specific assets-folders.
Finally: post back to the forums to tell us what you did (or even better: write a recipe, post it here: http://doc.silverstripe.com/doku.php?id=modules:external-authentication and/or here: http://ssbits.com/ and of course tell us about your post on the forums)
I hope I provided some usefull hints ;-)