If the existing floor has any kind of texture or pattern at all, it will show up right through the peel & stick tile. You probably also will void whatever warranty may come with the new flooring. The old floor also needs to be scrupulously clean: any dirt or grease or pet hair will cause the adhesive on the new tiles to not stick as well as they should (which would contribute to additional problems in #2 above).

You new installation will only ever be as good as what is there now. If you are willing to take that chance, then following the above advice should be sufficient. Additionally, if you do not have an voids to fill, instead of patching you can use a liquid primer to facillitate a good bond if the existing tile is asbestos. It its not asbestos, you want to scarify (rough up) the surface with a heavy grit sandpaper to facillitate bond. If there is any wax coating on the existing tile, that wax should be stripped before scarification, patching, priming, or installing new tile.

I know this thread has gone stale but I think I've found an issue with the LACK of subfloor prep: "They found composite tiles under the underpayment which neither we nor they knew about (it was coming up with the laminate removal so had to remove it all. We would have uneven floors) and that had to be removed so and extra $1000+ charge" I'm going to guess the removal of the composite tile (?anyone check for asbestos if the tile was from the 80's?) really mucked things up. The laminate was 'happy' sitting on the tile (I know...it wasn't supposed to be happy, but it was). The removal of the tile *MIGHT have caused some weird domino effect. I'm so sorry this has happened. It should not be part of your life to live through a shoddy bamboo install. With floating bamboo (click-together bamboo is notorious for issues...as in FAMOUS for having issues that reputable companies do NOT want to have anything to do with it) it is IMPERATIVE that all flatness ratings be taken. That expansion and transition strips are used through doorways. That all pinch-points are dealt with appropriately. Etc. If you are still dealing with this, please up date us. And if you can, please add photo re: doorways from hallway into other rooms (like the bedroom with the gap). And finally, bamboo is UNSTABLE. Laminate is very stable. I'm guessing the perfect storm occurred in your home. And another issue: bamboo needs +++time to acclimate. And it takes a special meter (an expensive meter) to take moisture readings of the bamboo (and then it takes someone special to KNOW HOW to use the special meter). I don't think you had anyone 'special' working on this project. I'm so sorry this has happened.

Yes. Of course it is up to you. It is your home. You have already voided the manufacturer's warranty so you might as well keep going. If this is a temporary floor that you ONLY need to be functional for 1-2 years, then keep going. No need to start over because you are ripping it out in 12-24 months anyways. ....BUT....if you want this to be a floor that is going to be in your home for more than 3-5 years, you want it to look GOOD. Now that you can SEE the H joints, you can never 'unsee them'. It will bug you to NO END! Guaranteed. So....you might as well learn the trade as it was meant to be practiced. Stagger your joints with as many lengths as you can. READ the instructions to determine the 'shortest' distance between two short edges (that means two planks sitting side by side....how far away their short edges are). Some companies require 4". Others want to see 6". Do NOT get let the short edges get any closer than that. And your doorway thresholds, the T-molding, do you HAVE them installed? You cannot run a laminate floor directly through doorways (like from hallway into a bedroom). You MUST have T-moldings that sit in the door jam. That's to allow the floor to float properly. And your expansion gaps? Are they present along ALL walls, door frames, cabinets, outcroppings? The THICKNESS of your plank is the SAME amount of space as is required for the expansion gap. Example: if your planks are 8mm thick, then you are required an 8mm expansion gap around the entire perimeter of the floor. Do you have expansion gaps around your floor? How about your 'last row'? Are you observing the correct 'plank thickness' required on the first/last row of the space? Some companies allow a sliver of just 4" of plank whereas others require 6" to the smallest sliver of plank on the first/last row. If you are scratching your head at anyone one of these requirements, then PLEASE START OVER. Please. If you had paid someone to install your floor like this, you would be SPITTING mad that they did everything wrong (again...this is an assumption that all of the above are 'issues'). Please prove me wrong with more photos and some measurements.