Waterfox is made by Mozilla
no, it's made by mr. alex, a student in cyprus who has been rightfully attending classes and doing waterfox in his limited spare time. the delay of v26 was due to his exams taking precidence as well as working out a few bugs in intel's compiler that stopped the code from working.
Most of those are things normal Firefox does (Like PGO, SSE, AVX, jemalloc, optimisation flags, etc.), and that's ignoring stuff like "Future Proof" (Whatever that means, WoW64 isn't going anywhere any time soon)
I also don't think using the Intel Math Library would do anything other than make the binary larger, it's a specialised library (Meant for scientific applications), and unless the code is changed to take advantage of it, it probably wouldn't do anything (Really the only thing it could be used for is matrix handling, but they already use optimised code for that) Same with using the Intel compiler.
The only functional difference is that you can use 64bit plugins, but since the majority of plugins are 32bit that's not really a benefit. And again, that's ignoring the actual issues the 64bit builds have (Currently Mozilla can't even do proper testing of the 64bit builds due to issues with them, so while they might work for a specific workload a end user might have, they're not stable enough for every day use for a large portion of people)
32bit firefox doesn't use any 64 bit optimizations. the 64 trial builds available in mozilla nightlies is not optimized and uses straight 32bit code. the 64bit pgo builds at mozilla are very dodgy bleeding edge trials of bug fixes. most of the other third party builds modify mozilla code in some way. mr alex uses the same code with just the mozilla mandated name/icon changes for the 'about' window. the intel compiler and optimizations should make a faster 64 bit version than the other 64 bit versions, none of which are as yet faster than the 32 bit versions because the code is written for 32 bit. compilers do not change 32bit optoimized code to 64 bit optimized code before compiling it.
PLUGINS like java (which you should not need to install, it's still insecure), and flash do require the 64 bit versions, which work perfectly well.
correct. mr. alex is a private citizen with no big corporation behind him, no funding other than his own purse, and no staff beyond himself. i salute his efforts and the years of time he has devoted to all of us sharing his knowledge and efforts..