The real question is knowing how many difficulty bombs will we have to face before ETH transitions from PoW to PoS...

It is a single bomb. I have provided you the link to see all the calculations. There is not hing more to this.
I know what the ice age mechanics is and why it was created. I was referring to the complete uncertainty about the transition to PoS. ETH mining won't last for long and there is no clear timeline for the transition to occur.
Let's not forget that the whole roadmap to Casper, including the ice age bomb, was devised when ETH was trading round the $7$8 dollar mark. The huge price rise and the tremendous expansion of the Ethereum Alliance might have changed the game completely.