Rewiring my kitchen, I have refrigerator, stove with electronic ignition, exhaust hood, and a microwave, and a duplex plug. Wondering if too much power for 15 amp breaker.

Thanks for any info.

If it is not tripping, apparently not. If you read the manual for the refrigerator, it will specify a separate a separate circuit for it. It may draw 5 amps or less, but on its own circuit, it is less likely ruin a bunch of food when something else trips the breaker. I have a least 4 circuits in my kitchen, refrigerator, microwave, most of the other outlets, freezer, plus a 240 circuit for the stove.

Unless the circuit is wired up with #12 wire, you can't replace the 15 amp breaker with a 20 amp. More circuits would be a better fix. Can't say if code requires them now.

I'm using 12/2 with ground. Trying to keep 15amp breaker in panel

A 15 amp breaker on #12 wire is fine. Not sure why that's what you want thou. I will tell you that the microwave may trip the CB if the frig is on, and should be on its own circuit.

A separate circuit for the frig is not required by code, but is certainly recommended, and, as Labman stated, may be recommended by the manufacturer.

What is required is as follows:

The kitchen counter is required to have at least two 20 amp "appliance" circuits, which may or may not have the frig on one of those circuits. All the counter outlets must be GFI protected, the frig is not required to be GFI protected. (You may if you like, you accept the risk of losing your food.)

I'm eventually rewring the entire house.
Should I use 12/2 or14/2 with ground I was assuming 12/2 was fine.

There are applications where 14 is allowed, but 12 is required any place you want a 20 amp breaker. Just buy a big coil of 12 and be done with it. I don't 14 is that much cheaper. If you are doing some 3 way lights you may as well use the cheaper and easier to work with 14-3.