I don't like the shakes much cold either so I tend to have the vanilla one hot and add a spoonful of coffee to it and it is ok then - actually quite nice. I have the chocolate hot too and make that with hot water with a peppermint teabag dipped in so it tastes like mint chocolate - lovely!
Re the shaker, I gave up on that and now use a hand blender as it takes away all the lumps and makes it smooth and frothy. I take the blender to work with me and to hotels when staying over and it's no problem - would rather do that than have lumpy shakes.
Give it a go and don't give up - it is definitely worth it I promise!