Veterans of PoE, is the game playable for a casualfag like me? 1-2 hours per day, 4-5 hours per day in weekends. Can I explore all of the game's content per league, until the league ends?
ALL of content? Sure, if you're a veteran AND you're really gud.
Here's the perspective:
1) The "story mode" comprises approx character levels 1-70 and will take you anywhere from 10 (efficient veteran semi-speedrun) to 30 hours (explore every nook and cranny, no rush, actually talk to NPCs, plus first-time player's learning time) reasonably. It features all of the basic features the game has to offer, but almost none of the stuff that gets traction on r/pathofexile.
Then you're off to maps - the real endgame. Here it's YOU who decide what's your goal.
2) Taking a character to lvl 85 (a reasonable endgame goal) will normally take you to t7-10 maps depending on your luck with drops and general skills. It will reasonably take approx 10-30 hours again, depending on a lot of factors, including the major one - how much time you will spend idling in hideout mucking about with different stuff instead of actually running maps. You will normally see most of what the game has to offer of the more advanced game mechanics, but you will not have seen the most advanced stuff in terms of gear, atlas mechanics, or what can be considered "difficult" content (not even close). You may have encountered some of the more advanced league-related mechanics, but likely not the top end of what the league has got to offer. The amount of "grind" (having to repeat content in order to advance) at this stage is fairly low - you will spend a good deal of time simply discovering all the maps the atlas has to offer at this point. We're talking about at least 50 varied locations that differ by layout and tilesets, plus each has a unique boss that may look like something you've already seen during story mode, but usualyl features some extra twists. Ideally, at this point you won't even have to run the same map more than once, while the game throws progressively harder things for you to handle, so the game still stays fresh.
3) Taking a character to lvl 90 (it's where a lot of less demanding veteran players usually stop playing and either make another character or drop the game until new content altogether, or take a break) will normally take you into actual endgame (red-tier maps) and will require approx 10-30 hours again, depending entirely on how gud end efficient of a player you are. The grind becomes noticeably more pronounced, you will have to run repeat content a lot more simply to progress to new map tiers, or to even find better gear to be able to handle the content you'r at. Depending on your luck and determination, you will get into t13-15 maps and may or may not experience t16 guardians (aka the pre-bosses of the very endgame boss), and you're likely to have failed miserably unless you're a veteran with the "right" build. You will have run the endgame Labyrinth. You will have found a good deal of various gear, maybe including some of the more exclusive stuff. You will have likely encountered the very endgame part of the current temp league, but likely only a few times.
4) Going lvl90+ means you want to get all the game has to offer. Beat the Shaper and farm the shit out of endgame league content, and get the best gear the game has to offer. The grind is officially ON full-time here - you MUST do repeat content ad nauseum until you acquire enough resources to be able to do cerain things better (or at all). Engaging in trading is pretty much mandatory unless you're super good at game. Not for casualfags like you, unless you're REALLY damn efficient veteran player who wastes no time on bullshit (basically, 1% top player).
Most of your fellow Codexians who actively post in this thread fall somewhere between groups 2 and 3. A couple go full way into group 4.