Is it correct?

1) The Sun is utterly boiling today. -> yes 
2)The previous winter was virtually freezing. -> there's nothing wrong with this grammatically but I don't think anyone would use "virtually". Saying "It's freezing" as a way of saying "it's very cold" is pretty standard
3) He hit me from scratch! -> No. If you mean he hit you without warning, then you need to use another phrase like "he hit me out of the blue". "From scratch" usually means you're right at the start of a long process. "Here are the instructions for how to make an apple pie from scratch" or "The dog ate my homework so I had to start again from scratch". 
4)I am going to learn Spanish from scratch. -> yes, this fits
5)In every sense of the word she is pushy. -> Yes, I suppose so. This would be quite an unusual sentence though, since "pushy" really only has one sense - the figurative sense (describing someone who tries to get their way by not allowing people another option) but if they literally pushed people with their hands while they were talking to them you might say he was pushy "in every sense". It sounds like a clever line from a comedy novel rather than something you would say in normal day-to-day conversation! "My manager was a real bully. He tried to browbeat the other members of the team, and if they wouldn't come round to his way of thinking he shoved them off their chair. In every sense of the word, he was pushy"
6)I want to go on either way. -> yes
7) The hardest part about my situation is by no means not become treacherous and false. -> No. I added the "the" at the start of the sentence but when I read on I realised the rest of the sentence doesn't make any sense at all. I can't even suggest an improvement because I don't even know what you're trying to say. Sorry.

Is it correct?

1) The Sun is utterly boiling today.
2)The last winter was virtually freezing.
3) He hits me from scratch!
4)I am going to learn Spanish from scratch.
5)In every sense of the word she is pushy.
6)I want to go on either way.
7)The hardest part of my situation is by no means not to be treacherous and false.