I missed 4 of my midterms due to illness (was admitted to hospital for it).
Can I submit a Msaf for it? Also it's been more than 5 days since my 1st midterm and there are only 5 previous dates available on Masf form, how do I then enter the date?
All my midterms were less than 29% except for one.

You should go through your faculty, and provide documentation. I believe for MSAF it has to be < 30%, so you cannot MSAF and will have to submit documentation if it was worth more. Also, it's supposed to be done within 5 days so that's another reason why you can't use the MSAF online. And there's no point in using the MSAF for some things if you're submitting documentation for others.