I can't really comment on the whole thing... because its really long... but I'll comment on parts.
Yes he can. Its shown later on in the game when (SPOILER)you attack Sin and he flies over Bevelle. He doesn't actually get on land, he flies over it, which is potentially worse.I want to stop for a moment and have you all appreciate that last sentence: at no point during the game is Sin ever shown as being capable of moving onto the land to wreck . It is depicted in almost all cases as a big and really angry fish. The place it's fought in the final battle with other summoners is a stretch of land right next to the sea. Apparently the people of Spira are retarded (like their church) and so don't just move inland to avoid this threat. Nevermind! It doesn't matter! Just a piddly little detail that we can overlook when necessary - what matters is our contrived and scarcely believable love story!
Blitzball was particularly easy, but this was no way the easiest of the series. In VII very little thought was ever needed, and VIII's level as you go eliminated the need of training. As long as you didn't overlevel there was a thought process in much of the battling to manipulate the turns, which I liked very much. Also The Dark Aeons and Penance were supposedly very difficult, I don't know as I live in the US, and can't get my hands on a PAL version.I want to close by talking about the gameplay. Well, more specifically, the lack of it. There is no challenge or intelligent thought involved in playing the game. If you play through every storyline battle and a decent amount of your random encounters, it is impossible to die. This is because you can't be bad at mashing X. The fact there were still random encounters in the game is also a testament to how horrible it is – any developer worth their salt would recognise it's an archaic system from a time when memory constraints stopped you from placing enemies on the overworld map. Apparently no one told Square, and we got a relic of a gameplay system to go with a poorly devised battle system. And Jesus, Blitzball. I almost forgot Blitzball. It's not possible to lose at Blitzball, either. Not unless you failed to get the Jecht Shot, which you can spam to win every game. There is no challenge to the game and there is no enjoyment to it – it's like a football game only it's crawling with pointless numbers.
I'd comment on more, but reading your comments are painful seeing as you can't make any reaction toward the game thats really worth reading.