There is no lowly "fan" that Toriyama is somehow patronizing. Here are the actual quotes in context from our translations, all from standard/traditional press interviews or supplemental material Q&A sessions:
The laugher item you've mentioned comes from the 2004
kanzenban guide book
Dragon Ball Forever. In Toriyama's Q&A, we see a question of "Was Yamcha able to become happy?" [In other words, "Did Yamcha ever find happiness in love?"]. Toriyama's response was:
Akira Toriyama wrote:He'll aaalways be like that. (laughs)
Toriyama is implying that Yamcha had perpetual bad luck with women, and the panel with him talking about how his girlfriend wants an expensive necklace reinforces that.
With regard the lives of several characters after the series asked by
Mandō Kobayashi host Kendō Kobayashi in a
Battle of Gods promotional segment,
Toriyama responded about Yamcha:
Akira Toriyama wrote:Like you, KenKoba, he has the dilemma of loving women but not being good around them, so he is still wandering blindly in search of the ideal partner he won’t be nervous around. He’s even worked in a host club, but because of his nervousness, it didn’t go well and he was fired. His livelihood is mainly working together with Pu’er as a freelance bodyguard, but he occasionally goes to Tenshinhan’s to help with the farm, as well.
I don't see a translation on our site with "had nothing left to live for". I'm actually struggling here to come up with these other items. Either someone's making stuff up (I feel like I've come across one of those Tumblrs before, and it was someone taking a quote WAY out of context), or... well... I'm missing something, but it's probably nowhere near what you're making it out to be. Will keep digging and see what else I come up with, but yeah.