So I've invested alot of money into warhammer the past few months but I'm ready to jump into playing. I love strategy games of all types and warhammer is a passion of mine in all forms of media. I've (badly) painted my army finally and I've been looking at army lists for reference. While I don't have all of the figures. I had kill team Cassius, a corvus, ordos xenos box set, death vets, captain, and a watch master coming via mail.

I say this to ask for clarification. I went out of order and have been studying how to play before learning how to build a proper list 😅. And deathwatch has always been one of my favorite factions even when I was a teenager they and chaos (don't kill me) were my two favorite armies to read about. I hear DW got mashed with agents and now everything for me is out of wack. I also been told I can use other SM units (I have a dreadnought for example, and terminators) as DW units? Besides other factions like tau and etc obviously, can I use ANY spacemarine model as DW? Does it apply to named characters? Can I get a breakdown in new player speak of a detachment? Cassius squad for example as a detachment has to have the units it came with? No switching? I'm trying to build a 2000 point army so any advice on how to do so, that way I can always build it myself without needing you guys to walk me through it would be appreciated. I'm thrilled to start playing and not many stores closeby to ask for help learning how to be self sufficient at list building. I'm a collector also so I can forsee buying new units all the time, so I'd like to know how to swap In units to always have a flexible army!