See I think here is where I differ from you. You're arguing that the proposed changes would make it more like a Test, I'm would argue that ODIs are now the lame cousin of T20s and need some differentiation. With T20 around, I don't mind if ODI cricket suddenly looks more like a 'one day Test'. To me, a one day Test would be much more interesting than what is at present just tacking 30 extra overs onto a T20. What ODIs need to find is their long term identity. What will help them stay popular long term?
On the 'one day Test' thing: in fact the commentators were talking about this the other night. With 2 new balls, and with pitches that seem a bit more bowler friendly here at present in Aus, openers are going to have to dig in more and opening bowlers will get more joy. I'm enjoying the opening exchanges a lot this summer actually.
And just on the 5 bowler thing: I personally think that while having to find 10 overs from all-rounders used to be a cool element of ODIs, it now annoys me GREATLY, to the point whenever Steve Smith or Dave Hussey gets the ball, I walk out , especially in the first innings where the batsmen won't take any risks (insert your own countries lame 5th/6th bowlers...Collingwood used to be a good one for Eng).
I think I used to like it because they were often different players than you saw in Tests, but now you see those players in T20, so there isn't much novelty anymore, it's just a chore that has to be suffered by both teams because you know batsmen don't want to risk getting out, and you know the bowling captains will be as defensive as possible to minimise any damage from loose balls. To me that is just a waste of time, no one enjoys those overs and I think both batting and bowling teams would prefer they didn't exist.