To reach platinum (maxed) dungeon experience, you need 40 runs (10 for each levels). There's equipment and items in the game, available in Chapter 1, that enable players to gain experience easily with a lot less hassle, and there will be more available when we release Chapter 2 update.
We do playtest our game. The full slot of bombs are there to check a lot of things, including what will happen when the inventory is full. We perform checks on how many bombs we used to defeat an enemy, in various character stats and levels, in various qualities, with every possible type of bombs that are available at that point of the game. We also check the average pickup rate on multiple dungeon runs and cross check the data back with other aspect of the game, including the Warrior's Guild inquiry and battles.
As we said in our previous reply to you, the store mechanic will get some overhaul in Chapter 2 update. Each items in the game has an map to customer types that will buy them (Shprucia extract for instance, will only be bought by male customers). There are also other values that are currently invisible to the players. We will be upgrading the UI to better show these values to players, along with other mechanic improvements.
Repetitiveness will always be felt in the game, since the core mechanic revolves around running dungeon - gathering resources - crafting new items. People rant about adding new and strong weapon (with infinite uses) for Charlotte to wield, something that we will not be adding to the game since they will break this cycle and destroy the game concept. We already introduced a lot of features since initial release to ease up aspect of the cycle: encounter reduce, crafting mastery, dungeon experience. The upcoming gardening feature will add more to this, trading a bucket of fresh water with a constant supply of ingredients that they choose.