battery charging - What happen with cells with different current rating put in parallel?

I don't understand how cells behave when connected in parallel. So what if I have two Li-Ion cells: one ist "rated" at 15 amps (which means that the cell is able to discharge at 15 amps without problems , right?) The other cell ist rated to 5 amps. Now assume both have appropriate same Voltage to connect them both in parallel. What happens if you connect a load which would draw 10 amps now? Would both cells try to discharge with the same 10A (and thus the 5A-cell would overheat and fail...), or would the current be spread up eavenly? Is it actually forseeable at all what would happen, since it depends on the internal resistance of both cells, doesn't it? Does someone know what would happen?

Then another question: what if you put two cells of different capacity in parallel? Isn't the cell with the higher capacity supposed to give more current? Because the discharge curve of the high-capacity-cell is above the discharge curve of the low-capacity cell. So the high-capacity-cell would have to discharge more of its current until it decreases its voltage to the same level as the low-capacity-cell? So would that mean that the internal resistance gets lower with a higher capacity, is it proportional?

Hopefully my explanations aren't to confusing and hopefully there are people who are bothered by the same question :) Thank you!