All the images should be the same color type and match the color type you set for the document. All rgb or all cmyk. For commercial printing - all cmyk. If you're just printing off a common, non postscript inkjet, they recognize rgb. This should not effect any crashing, but who knows.
When you export to pdf, you can select color mode under the Advanced tab, however color mode should always be the same for the doc and all images before export.
I can only think of 2 reasons you're crashing - lack of ram or screwed up ID preferences. You can try the ram thing by closing all apps and restarting - to clear any memory allocations from the machine. Then just launch ID, nothing else and see what happens.
If you use a mac and want to trash ID prefs go to User/Library/Preferences. Pick Indesign and trash. Make sure ID isn't running. To trash prefs on a pc you have to do a search (with show hidden files enabled). Unfortunately, I do not know the name of the ID prefs file in Windows. Hopefully, someone else here does. If so try trashing and see what happens.
OOPs! One last thing I thought of. When you installed ID, did you have all antivirus software turned off. No applications should be installed with AV enabled, since it might identify one or more parts of the install as virus and mess up the install. If you did install with AV active, you might consider uninstalling and reinstalling.