I have the same problem with the adhesives as they can be a bit hit or miss in quality, even the 'real' 3M stuff.
I agree completely with Brent above about the thinner less tempered replacement glass but for a few €£$£€, as above ^^ what can u do?
I repair ipads/phones on the side so have tried different things but this is what I use and do....
I use plastic clamps that you can get from the poundshop (UK), you can 6 for about £1 so two or three packs is more than enough,
but as Brent said above the glass can set with too much pressure causing an oily-like distortion where it presses on the LCD which can mean removing the glass again (absolute pain in the arse) but a suction cup can help as suggested.
Anyway, long story short I use a mix of adhesives and a good strong glue that doesnt cause any corrosion, clear and easyish to remove plus holds glass well. EVO Stik Serious Glue/Gel
It's about £5-6 but lasts ages...dont know if its sold in the US though.
I only tend to use it in the trouble areas where the adhesives are quite thin which is by the digitizer cable side. I also put blob to the right of the wifi antenna on the black plastic speaker.
I then hold it for a few hours with the clamps evenly spread around the screen but keep an eye out for the oily distortion.
Only bad point is like most glues it is a complete nightmare if you get a bit on the lcd. ..but cleaned quickly and with proper cleaning fluid will come off.
Like Brents alternative it can dry with a white colour so u need to be careful with how much you use so there is none squeezed out the side between the plastic frame...but it only tends to affect the black ipads...it does come off the glass front reasonably easy with a decent cloth and alcohol.
Hope this helps....and I might have and look for the Permatex RTV and give that a try to compare.