It seems, I am conservative, but I think, it is his DUTY to marry. That´s the position he´s been born in. Full Stop.
Can you tell me ONE reigning royal, who did not marry?
I completely understand, that it is not easy finding the correct wife for this role (especially as Gracia was an icon in her position -- and Caroline has a lot of grace and style, too), but
1) he has had enough time
2) it seems, that he has the right person now.
In my eyes it really seems, that there is a deep love between those two, which already lasts since a couple of years now. And to me Charlene would be a real asset to the Monegasque Family.
I rather think, that he still wants to give her some time to prepare and to learn better dealing with the press... but sooner or later this "preparation time" should be finished.
Of course there is the possibility to bring Carolines children to the throne - this has happened in other countries as well, where the Souvereign did not produce a heir, such as Belgium as an example..... but the difference is, that i.e. Bauduin & Fabiola had several miscarriages, whereas Albert DID NOT YET TRY IT UNTIL NOW.... (and children like Alexandre does not count here, they are already excluded from the throne).
As mentionned, just my opinion
BYe Bine