Extreme noob questions connected to Grail Knight and playing Vermintide 2

Hey

So I've come back to this game recently, I never was any good(22h in game currently), grail knight got me interested so after some dwarf games I went for him.. and it made me question my whole gameplay

this link will be important, I'll refer to this guide:

https://steamcommunity.com/sharedfiles/filedetails/?id=2139200953

So the way I've been playing the game is plain simple, heavy attacks only for elites and first hit of hordes(until today I didn't even know you can combo heavy attacks, I somehow never thought of doing that), other than that during any bigger waves I was always doing, regardless of the weapon used, push spam 2-3 light attacks push spam push spam.. only. In this guide you can find instructional videos for combos, I didn't even now there are combos(like push + light attack in case of sword and shield pushes enemies away and then quickly light attacks them with shield)

1.

This brought me to questioning my whole gameplay idea.. so I guess first question is, have I been playing the game wrong this whole time? It seemed stupid simple with push light attack only strategy, at this point I'm very confused as to how to determine if someone is playing well or not, and I definitely can't determine if I'm doing any good

2.

Second topic is strictly about Grail Knight, so I am using Bretonnian Longsword and Bretonnian Sword and Shield. The way I figured out to play is use longsword for elites and single enemies/small waves while sword&shield is great at handling big waves since shield has such a nice push angle, good blocking angle etc etc.. I did notice that the sword from sword&shield set does strangely lot of damage but I ignored it since longsword seemed to be bad at crowd control with its attack speed while sword&shield are naturally better at it

So now I'm confused if I identified roles of these weapons correctly. And that's question number 2, how should I think of these weapons?

3.

Last question, naturally number 3, is a weird one. So just now I learned that Bretonnian Longsword's heavy attack serves as a block, guess I should've realized that by the 3 small shields appearing when it's being held up, but I didn't. I noticed that when I hold LMB only for a second or so the heavy attack "locks" itself in, whole animation of GK putting his longsword up plays out and only then I can attack. Is that okay? I feel like this locking slows down ability of heavy attacking continuously, but I'm really not sure. It's also annoying that because of that I don't always know if the heavy attack will go off atfter I let LMB go, or after I press it again(which is the only way to set it off IF it "locked" itself in for the animation)

I know, that's a lot of text. I am really confused about.. even about what I don't understand, so I don't know how to explain it briefly..

Of course I numbered the questions, so if you want to respond, thanks! And feel free to mention "only" one of the topics if you feel like it!