You speak in what if's with little knowledge of the subject or that mater what "miners" want. No alts for starters... A larger block size would solve transaction limits as was the original intent.
Did you read the posts?
Adam wrote that it was so difficult to get consensus on even trivial changes like increasing block size, imagine on postponing the halving. I just pointed out that the miners will have no monetary gain with larger blocks, but would have a huge one with the postponement.
Last time I checked, the top 4-6 miners had more than 51% and were all in China. Do we know what they may want?
Since that "attack" would not be risk free, the top miners will not want to risk it unless they have much more than 51%. Also, if the price more than doubles before that, say 800 $/BTC by early 2016, they would probably regain a comfortable profit margin and may be happy with it.
But with the price at 800 $/BTC, on the other hand, postponing the halving would give them ~500 M$ of extra revenue per year...
Sorry but thats bullsh*t, if the block halving changed the price would crumble. So they would have no monetary gain at all. It makes no economical sense, you suggest that the miners could agree on it and everyone who pays their bills (the buyers) would just be like ah okay. Not gonna happen.
Edit: Lets also not forget that 51% is where it becomes possible, its still a hard thing to do and to pull off succesfully would likely require much more than that.
I might have fallen and hit my head, but I thought the 51% attack was related to transactions. To change the halving you would have to change the bitcoin client. Those "bad miners" would be mining an alt.