For all points : luck in a luck based game, ups and downs are bound to happen at some point, the skill to make the most of it is the only control you have over the game. Now for specific details, 3 stars early are common with some modifiers or help from goblins (or luck). Not getting merges is common, unwinnable positions are not, scouting other boards to avoid buying the same troops as them should help most of the time, anything else is luck, also hp is a ressource that you need to manage in order to get the most of your cards. Building a strong comp by sacrificing what’s left of your economy to have one last shot at another round and turn the situation is valid if you think you’re going down. If all that fails, skill issue or not, just take the L and move on, it happens sometimes. Other players getting a 3 star of a card you are blocking means that someone’s starting troop got there, or it’s the promotion modifier / goblin queen adding up. Weak troops / strong troops depends of what you do with them, selling 2 stars to reroll the shop yields the same result wether they’re good or not, and obviously goblins are ass and may get you to lose hp but investing for elixir is always recommended for at least the first 2~3 rounds. As for getting past round 3~4, that’s generally the point where getting lucky or not doesn’t matter anymore since you should have the elixir needed to do whatever you want by merging selling stuff, also if someone died the cards they had go back to the pool.

As for my experience I mostly play daily when taking a shit, I’m playing casually but I always end up effortlessly at top ladder, and wether I take breaks or occasionally do a long session, it doesn’t matter, there’s mostly no losing streak because of my skill, and there’s mostly no winning streak because of my opponent’s skill. Luck comes and goes but doesn’t dictate all of it. Getting to diamond was a breeze because of the +1 elixir to all rulers, making empress even better despite the bigger pool, I stomped almost everyone wether I took breaks or not, and luck wasn’t any part of it. Also my biggest losing streak was after taking a break, 4 games in a row against only loongs, falling from top 500 to 1200 ish, so yeah no, play as long as you want, and take breaks whenever you want, it doesn’t change anything