Shaper seeds are tier based
There are 15 total (not linear distributed across the tiers). Not trade-able quest rewards for either slaying the map boss or doing the map quest (opening that shitty chest, thanks Vorici). Shaped maps get +5 to their Tier. Non-shaped versions won't drop for you anymore, at all. Shaped versions are still restricted by the map drop system. Meaning you need to be at the same or higher tier than the shaped map you want to drop. This doesn't increase drop rate of higher maps. Tier is rolled first before the layout on drop. Reverse cost is 5 Regret + 20 Chisel.
I would really like to believe that it is something different, but looking at the mechanics it's just more of the same. You just have to grind for the layouts, rewards except for some mods are the same. Farming a specific map doesn't increase it's drop rate, it will just narrow the layout down. The benefits are to the market though. More map trading probably.
You'll get it back. What he didn't mention was that you'll probably also need a shaped version of that map (else just putting 20 chisels + 5 regret into the vendor without any pointer to the map would be quite stupid). On shaping a map the orb is consumed ofc.
Depends on how many "bullshit" one shot mechanics they have and how difficult they are to dodge. Lot's of builds are "top tier" thanks to ascendencies.
"Optional" meaning you can just yolo through like before. Content is the same, just with different mods.
Transparent information and not ninja nerfing is not their strength. Especially after all the xp and map drop nerfs (minus the fix for the horrible first iteration) you don't really expect them to give out more high tier rewards. Best case scenario it will equal out to +-0% at red maps, a slight bonus to yellow maps (which everyone already has plenty of), and tons of low tier maps that are left lying on the ground anyway. Same as before and no one will notice.