Need help to understand solo mining process

I'm new to mining and trying to write simple program in C# for fun to really understand how it works. I know there are several posts on this, but some are very old and doesn't really explains on how server behaves. Please correct me if I'm lost in basics understanding of process.

I'm using ckpool solo mining for my testing

1. When I connect to pool, I keep receiving the request mostly every 1 sec that contains the array of transaction ids. I understand I have to use those ids to calculate the Markel. But block is created only once in 10 min, so why I receive so many requests to work on.

2. What to do when I receive multiple requests with same PreviousHash parameter? I read in case of solo mining, I have to drop existing hash process and take the new one to work on.

3. Markel is also part of calculating the Nonce, how server confirms validity of solved submission if we don't submit the Markel that we calculated from the transaction ids we received. Server might have updated the transaction list by the time mining is in progress.