When you use the 'sticky tools' option, if you hold down a key, like the 'T' and then tap the space bar, it will change the selection to the selct tool as the default. If you then hold the 'M', you can use the marquee temporarily. If you want to switch to the marque as the default, hold the 'M' and tap the space bar, and then the marque tool will be the new default. I also have a lot of problems using a mouse or a Wacom tablet for selecting vertices, but the marquee comes to the rescue as VK said. Good luck! :>