1. you don't need to add sga_max_size in the pfile.

2. if you are using ASMM by setting sga_target parameter then large_pool_size will be maintained by Oracle.

3. in 10g SYSTEM tablespace by default create as LMTS. So you can't create any other user tablespace in DMTS.

why do you want to create DMTS? LMTS is the recommended method by Oracle. Any specific reason for DMTS requirement?

Thanks,