To freeze rice just cool it really quickly by putting it into a seive and running it under cold water until it is cold, then freeze it.
Pues can be frozen, yes. I'd cook them and then freeze then if we're talking about pastry pies like cornish pasties or something.
Other good pies to freeze are fish pie and shepherd's pie with potato toppig, and chicken pie made like fish pie. Yum.
Pizza bases I also part bake, then when cold wrap in cling film and stack on top of each other in freezer. I do this with home made pita bread and naan bread too. Home made bread I just cook and then freeze.
Almost anything can be frozen, certainly all sauces, pasta sauces, curries, casseroles, bolognese, cheese sauce chilli con carne etc
Lasagne is another good one to batch cook and freeze.
I make very concentrated tomato sauce for pizzas, os it is basically condensed, by cooking off most of the water over a slow heat, then freeze it in ice cube trays, then I take one cube per pizza, defrost and add some water to make it less condenced again.
Noodles don't freeze well, I learnt by experience, but who needs to freeze noodles?
Couscous freezes well.