As has been pointed out in the comments, the first example is the least used (although a quick search on Google Books still returns several hundred examples of published use). Of the four though, it's the only one that would sound wrong to most English ears.
The other three are all in common use. The suggestion that #3 is, in some way, incorrect is just plain wrong or is misunderstanding a (fairly loose) rule.
You have to look at the way 'surprised' is being used.
If it being used as a verb then the writer is correct - it should take much as the modifier. If it's being used as an adjective, it can take either.
Take a less ambiguous example - the verb 'Praise'
The work was much praised or The work was very praised
Here, because 'praised' hasn't made the jump from verb to adjective 'very' sounds wrong. 'Surprised' though (like interested, disappointed, confused and many others) can be used in both ways.
Again, as has been eloquently pointed out in the comments, English is a dynamic, evolving language.