Your phone shouldn't lose any information if you decide to switch the sim card. The sim card doesn't have to do with apps or anything of that sort, it deals with the connection to the network. Hope that helps answer your question :)
Some people do store their contacts to the SIM. So just make sure you sync your contacts to your mailbox account before you do the swap. If you're already using your email for this then when you swap everything will be there for you.