It seems to me that the "from" is unnecessary and perhaps redundant.
Learn English – Do you “prevent somebody doing something”, or “prevent somebody [from] doing something
prepositions
Related Solutions
There is no rule here, but "mixed feelings about" is far and away the most commonly used expression. Check out this google ngram graph for the following four constructions using "mixed feelings + preposition":
- Mixed feelings for
- Mixed feelings on
- Mixed feelings about
- Mixed feelings to
While all four constructions register in google's library, "mixed feelings about" is the one most people will recognize. As for differences between the two examples you've provided, I can see no clear distinction. Furthermore, if you use "mixed feelings" with another preposition, chances are people will understand that you mean "mixed feelings about."
Doing something 'to' somebody would imply that something was done to them directly, whereas to do something 'for' somebody would be on their behalf.
Example: To: I hit Matthew. For: I sent a birthday card to Matthew's mother from the both of us.
Best Answer
I think unnecessary and redundant are somewhat "loaded" terms in this context. In fact, we usually do include the preposition "from"...
...and I think only a pedant would argue for or against any of those three, in almost all contexts.
Comparing UK/US-only usage on that NGram suggests Brits may be slightly more likely to omit "from", but that hardly seems significant. The main factor affecting usage for all native speakers is that we're more likely to drop the preposition in simple constructions. Thus...
...is immediate and unambiguous (though many of us might prefer "stop"). On the other hand...
...is something of a garden path sentence. I highlighted the word "from" so you'd see it coming.
If I hadn't highlighted the word, you might well have assumed it before "watching". And then been forced to re-analyse later, when you finally came to the actual word explicitly stated. Which could have been even later - I could have written "You can't prevent an unemployed person watching daytime TV drinking too much from dying young" (forget the missing "and's" and commas).