I have considerable experience in writing programs that need a rigorous parser. Also, I've been using linux for a long time now, so I understand the project requirements well.
As far as I see, the parser will be required for only the shell built-ins and the features the shell provides regarding job control and i/o. System commands do their own cmdline parsing. So I think coding everything up and finalizing shouldn't take more than 6 days. At most, 7 days.
Looking forward to work with you. Thank you!