Not sure why you're bringing up kernels...
If you want Bukkit/Spigot support you can write it yourself if you know how.
There will be no official support for Bukkit/Spigot and you won't receive support in this venture.
Forge looks for certain markers in the file to determine if it should be treated like a mod, Optifine currently does not have any of those markers so it's not detected.
No, but usually renamed jars indicate that mods were sourced from an unofficial source which may or may not have done nefarious things with them.
I would suggest making sure all your mods are updated.
Assuming you mean allocating more, you need to launch the server with a batch file or shell script (depending on your OS), through the use of -Xmx and -Xms
Oh I thought you were referring to an install issue, rather than a launch issue, my mistake.
Yeah the data and extra jars were merged recently, evidently the server is still expecting them as separate.
This is on Optifine, if they want their mod to be loaded by Forge they need to add the bits that Forge looks for to identify mods.
(for Optifine the process is actually MUCH more involved than that, but this is the bare minimum).