Is there any shortcuts that have already been made that can go through my entries and change &, <, > and other common characters to their html equivalents.

This is required to not break a page's validation just by adding a post.

See the information on encode_html and encode_xml in the template tags section of the MT manual (under global tag attributes).

You wouldn't want to use those attributes on the MTEntryBody tag in your normal templates, because then it would convert characters you don't want to convert - such as in links, the breaks MT adds, and so on.

I use a decoder bookmarklet when composing entries to convert certain characters.