I'll answer your questions

is the cage the current owner of the fifth key

Not anymore! More on that... later

What if offer my hands as tribute?

You cannot offer what you can't even produce! Your hands are gone in every instance you need them

now, shrek three on the other hand, that was garbage

shrek four saved it

THIS ISN'T A QUESTION, for stating opinions, you have been given the Junior Opinion Ribbon. This will denote you as being HUMAN.

What's "being an ogre" a metaphor for, given the plot of Shreks 1 and 2 as viewed from a modern socio-political context?

It just means doin y'r own thing and hanging out 'n a swamp with all your buds

How many roads must a man walk down?

As many as it takes to get to Rome

What stats does Gerald have? Particularly its ATK. Same for the cage, but I'd like to know DEF of that one. Any special abilities they might have that I need to be aware of?

Gerald is... no longer with us...

How can you not know who Max is? Have you no shame?

Thanks to a head injury! I have a little shame.