Praying.... haha don't worry about being chicken! I too am always concerned about my appliance fitting perfectly. I mentioned before that I use the coloplast extended wear and have been really happy with them (though my stomach is flat around the stoma--is yours?)
I think you can use eakin seals with them if you want...I do not; I just measure mine really close--I have to get it cut perfectly or I throw it away! (Good thing my insurance pays 100% and sends me more than I need--but usually get it right the first time:) I found that my stoma is close to round, being 30 cm from side to side and 28 cm from top to bottom, so I cut the wafer this way.
Anyway, you can tell if the bag is snapped on because you know the little plastic thingy on the bag that you push together so it snaps, and press to open if you want to take the bag off? Well, it will only snap shut if the bag is completely snapped onto the wafer. Does that make sense? My stoma nurse told me this, bc like you I always wanted to be totally sure!
I actualy use paste also (that is how my stoma nurse taught me), and I have had really good luck with it. If you do not cut the wafer perfect, the paste can fill in the space around the stoma. Though paste can be messy if you are not used to it... :) I remember when I was just lurking on this board before I got my ileostomy and would read Summerstorm's tales of paste and think "OMG, what is this 'paste' stuff? I better stay away!" lol. Good luck. I hope they work as well for you as they do for me! :)
Let us know. :)
E