People lack respect for Dany because she's a woman. People lack respect for Jon because he's a bastard whose last name is Snow. These snap judgments can be surmounted for Tyrion just as they can be surmounted for Dany and Jon.
True, sort of. With Jaimie (supposedly) trapped by a vow of celibacy, Tyrion was the only hope of continuing Tywin's line, as disagreeable as the thought was. He didn't want Tyrion getting emotionally attached to a whore when he should be impregnating a respectable high-born wife like Sansa.
Dorne's fleet will matter as much as the show writer's desire it to matter, and not a whit more. And we have yet to see Highgarden's fleet. For all we know Euron will catch Dorne by surprise and sink her entire fleet. We can't assume anything at this point, because the show writers will do whatever they think will make for the most emotionally charged story, and easy battles for the heroes do not make for an emotionally charged story.
If Yara and Theon had an equal or greater sized fleet why didn't they simply go after Euron and kill him? Why is it that they were the ones who fled?
I think the show was a bit confusing because Yara's fleet was never really shown, and the number of ships Dany needed was a bit unclear. The size of Yara's fleet in comparison to the fleet captured from the Masters also wasn't really specified.
I promise you, Euron isn't going to simply disappear now. Mark my words. He will be back. It's pretty obvious to me.
And Euron will likely have the Dragon Horn and an even larger fleet. It's not going to be an easy fight. She will probably win, but it's not guaranteed. It depends on whether the show writers will be content to simply give her a tough fight, or they want to up the seuspense by dealing her a significant setback to make her work hard over another ep or two to turn things around.