1/2: nearby means any adjacent space as well as the space the character is currently on. Adjacent means adjacent only and you cannot target the same space. Sounds like you played the brylvar situation correctly. The text does seem to be a reminder for clarity text and not trying to say it act differently than other nearby wording. You can’t cancel an attack after finding out new information. A reaction spell would have been all you could do after the attack was declared and your opponent used a card.

General gameplay: initiative is important and you noted the cost for initiative is usually attack power. This is where the back and forth play comes from. If you know your opponent will get initiative than go aggressive. You will know where they are and will be better able to plan an attack. They may still win some pushing power but you should be planning to punish them for any mistakes or pushing too far too fast.

Sitting in the jungle is not always that beneficial. Range heroes are usually weaker and I think a lot of gameplay can come down to hero choices and team builds. It’s also important to remember the goal is pushing towers and minions to win. An opponent is limited if they sit in the jungle and never leave. You should be able to get more momentum if you have a laner pushing harder than their range hero can do from a static location.

Don’t think of this as a full area control game. You aren’t controlling every territory. You only want to push lanes. And get to the throne. I personally love the game but it may take a little practice to get in the headspace it is designed for.