The things is that there
are valid reasons for all those features: JS-based redirects are useful for many webapps, blocking text selection can be useful for some buttons and such, many people
do use custom app-specific key mappings, overriding right-click is useful for many apps (e.g. Google docs), etc. etc.
Of course, all those features can also be abused, but that doesn't mean it's a good idea to try and second-guess website authors; that just makes things much much more complicated for everyone.
Any feature can be abused in any platform, and as the web has moved towards an "application platform" – instead of just a document viewing platform – there are many more features with potential for abuse, but it also becomes much more important that behaviour is consistent and predictable.
I'm most definitely not on the "the specification is holy"-side of things, but from what I read in this issue the Chrome team seems surprising tone-deaf to concerns about Chrome's behaviour here. This is general patterns I see with Chrome, which confuses "it works for the majority of cases/users" with "it works well". These are simply not the same things.
