Will computer knowledge reach a perfect game, after expanding prepared openings/endgames? If computers just check in an openings-DB what to do in the first 10, 15 or even 20 moves, and if they just check the endgames-DB at the endgame; wouldn't it reach a point where they have a DB of perfect games that goes from opening to endgame?
To my mind, what you are asking is can a computer ever "know" the correct move and evaluation in every conceivable position. Without such complete knowledge, it wouldn't be possible to play perfectly because every evaluation is dependent on evaluations of the multitude of possible upcoming positions. This perfection is what endgame tablebases provide. Outside of contexts where distance to mate can be calculated, tablebases are the only context in which computers have a "perfect" understanding of a position. For reference, 5 piece tablebases (e.g. 2 kings and 3 other pieces) require 7 GB of storage. 6 piece tablebases require 1.2 TB, and 7 man tablebases are only recently completed and require 140 TBs. To solve chess completely, you would need a 32 man tablebase.

The problem is comparable in fictional magnitude to the calculation of the "Ultimate Question of Life, the Universe, and Everything" as depicted in Hitchhiker's Guide to the Galaxy. In that case an entire planet, was devoted to identifying the question. It seems an equally pointless and gargantuan task to attempt to "solve" chess.

Just to put your mind at ease... even though computers may play well above the level of the best humans today, there are still plenty of decisive games between top level computers today. Check out the ongoing TCEC tournament. Clearly, computers are still quite capable of mistakes.