Pretty much agree with all you said, particularly about Vinnie being a downright terrible character. If this is anything more than a goof, Family Guy's coming off my to-watch list, not that it's there for any other reason than just killing 20 minutes while I drift off to sleep.
The episode was also completely awful and deliberately designed to kill Brian. Non interesting story, barely a funny joke here and there, Stewie destroying the time machine and then is unable to build it again because, with all his technology, he only has the one guy that supplies him with materials, two of them playing hockey in the middle of the street and Stewie needs a drink... yeah, it's all just designed with no other purpose than to kill Brian off, which makes me think that it's either a goof to spice up the ratings (particularly with them having announced killing a character off and considering the following episode names) or possibly, that it's the kind of bad writing that could make Vinnie look like an interesting character. Kinda hoping on the former as I did still enjoy Family Guy here and there even in these later series and I'd hate to see it turn to complete crap.
Btw, title/subtitle - cheers for the spoiler. Dog.Gone + "something important happens on an animated show" with a bonus of you actually talking about it, could've been a tad more subtle around the whole thing :\