[using multiple plugins, discussion] Am i asking to much of WordPress?

I want to do something like this. I would like to use something like Sabai directory, but under another menu item(so another page in the theme) I also want a job listings plugin. Is it possible to get several big plugins working together. Maybe they would need to pass data between them? To extend this example it would also be great if I could have these things working with buddypress. So how would the security and login things work together, I guess they cant? So you would need separate logins for each plugin for users to use features like be a member of the social network, to post and pay for a job listing, and post and pay for a directory entry. Payment is another example of the same problem, what if the plugins use different payment processing gateways, or even if they use the same payment processing, maybe there would be a conflict between the 2 plugins?

So back to the title of my post, Am I just asking too much of WordPress?

Thanks in advance for any ideas, or views

Paul