I can recommend Scour as I have used it a lot myself when cleaning off unnecessary cruft from SVG files, which is something of a hobby of mine.
An example scour command line which might serve you well (and which I tend to start from):
scour --enable-viewboxing --create-groups --shorten-ids --enable-id-stripping --enable-comment-stripping --disable-embed-rasters --remove-metadata --strip-xml-prolog -p 9 < old.svg > new.svg
Be sure to compare the old with the new to make sure it didn't wreck anything and try lowering the -p decimal precision (the default is 5 if you don't give one); at some level it probably starts distorting things pretty badly, but one or two decimals higher should look good.
If you want to take on a more manual approach, there are lots of tricks of the trade gathered in the Kilobyte SVG Challenge changesets, which are meant as a kind of combined learning and teaching place for this kind of thing.
Yes, you can embed a font in the SVG file, or link an external one, as demonstrated by Mike Bostock's take on the WebPlatform.org logo (non-html-wrapped version here).
It is of course far easier to accomplish this if you have detailed knowledge of what fonts are used than if you pick an arbitrary pdf and convert it; I do not know of any tools that create a no-name font from whatever glyphs the original pdf embedded without you doing most (or all) of that work yourself.
Furthermore there is a growing list of SVG optimization tools in the Kilobyte SVG Challenge README's Tools section.
