If you can, I suggest getting an experienced IDPA or IPSC shooter to check your overall grip in person at the range just in case. Consistency in position is really important, and its repetition that will make that position feel comfortable and natural.
Once we all give the signal that we're gripping "naturally", our instructor always marks a line across our thumbs where they press/fit together so that our grip position is always consistent throughout the practice session. Consistency is important for which part of your pad on your index finger you use to pull the trigger too, because if you change that during a course of fire you'll often unconsciously shift your entire grip as well. Then you'll wonder why you aren't hitting alphas anymore.
I'm not a big believer in dry firing by balancing items on the slide, or using lasers to see if your gun moves. If you use a laser, you'll be looking at the dot on the wall - not at the front sight. Already you're practicing bad habits that will be incredibly hard to break later on. While properly focusing on the front sight, if you jiggle the gun even a tiny micro amount while pulling the trigger, you'll see your front sight move in relation to the rear sight (and/or target). If you can't call your shots while dry firing in the comfort of your basement, how on earth are you going to do it live fire at a match while running?