Probably the clearance setting for your track can’t be enforced because of the central pad. You can either escape the pad with a smaller track that is connected to your 1.0mm main track, or (my favourite option) you can use a copper pour zone for that pad connection (it helps with removing heat from the LED).
Indeed, if you look at the datasheet you can see that continuous copper areas are recommended. The H shape isn’t important, it’s just a suggestion. You can for example add vias to it and another thermal copper area to the bottom of the board.
First of all, don’t use copper polygons on your footprints - it’s a really bad practice and should be used very, very carefully for very specific use cases.
The central pad of the LED should be built as a pad, not a graphical polygon in the copper layer (they are quite different things - the pad will link to your schematic, while the copper polygon will be a bunch of copper where you can’t connect anything - not very useful).
What I was suggesting was that you put your footprint on your PCB and then you should add a “Filled Zone” (look up the icon “Add Filled Zone”) - this will let you associate that “zone” with a specific net and if the zone covers the pad, it will make the necessary connections.
No problem. I hoped that there was a translation error there. You can edit your profile to give a location (as general or specific as you desire, for example I give a general “Northern Delaware, USA” instead of my specific city). That gives us an idea what language you might speak.
This looks strange, the thermal reliefs are missing. Did you press “B” to update the fills? Maybe read a tutorial on fills?
The fill sould be wider so you get connections to the sides as well. Try to replicate the example tiagogala posted above.