Which would we 'like' to see removed first? Or which do do we think 'will' be removed first? Because there's a huge difference between the two...
In response to the question - and I'm sure it's one that will be echoed by many of you - Submission. No contest.
The response to the other question is a far more complex one to formulate - largely because nobody really knows. The sad truth is that Submission is unlikely to be leaving any time soon (not unless someone in park management realizes how disgusting a blot it is on the face of their otherwise respectable ride selection).
The only reason I can see The Blade being removed any time in the foreseeable future is due to either a catastrophic failure, resulting in it simply becoming easier to replace than repair, or Towers wishing to replace it with something else altogether - which is unlikely. It fulfills its intended purpose perfectly adequately as it is, and simply isn't a big enough concern for the Resort to warrant spending money on an identical (or indeed, similar) replacement.
Ripsaw is an entirely different case. It's a ride that has always been hugely popular - yet has really started to show its age in recent years. At what point will Towers realize that all the removal of theming, temporary repairs and other cut-corners are simply too much? And will that day come before or after the ride's inevitable failure to operate to a commercially viable capacity? Who knows?
You'd have to be a fool to seriously attempt to determine Enterprise's remaining life-expectancy. It could be gone tomorrow, or it could still be kicking around in ten years' time.
The Resorts' decisions on such matters will always be financially motivated. The day they have reason to believe a ride (or the space it occupies) could make them more money in the long run if it were to be removed and replaced with something else is the day it'll be earmarked for removal - it's as simple as that.