People are talking about guardians for Eldar and scouts for Space Marines as starting characters and you progress from there. My question is how do you think each faction will progress

im not sure if that's the case I heard there is going to be five or four classes for each faction so my guess would be yes you would start as a lowbie but it depends on what you choose like the scout would be its own class where he could probably go stealth/sniper or speed/shotgun damage specd but that's just what I think will happen.

I would rather believe it would be more like in PlanetSide2 (PS2 for now on) where you have multiple classes from which to choose at start. Your regular Space Marine will be the default option and others (raptors, teminators, etc.) will cost you points to play, much like MAX class from PS2. If you loose a unit, let us say terminator for instance, you loose the points you have and have to gather more to get a chance to use the special unit again. Leveling different classes gives you access to new gear, such as weapons, armors classes (ranging from regular power armor to artificer armor for example) of varying designs and values. Also leveling classes may give you marginal advantage in damage and armor values while changing design of an armor or a weapon will give you different playing experience when you have to choose from having more armor or moving faster for example.
There even might be different progression to classes and overall progress. Overall progress would define your overall rank in game starting from lets say ordinary line man to captains. This would open up room for competitive play. When you reach the rank of captain your performance in battle determines your ranking among other captains. Preforming better than other captains in general will give you access to even more rare rewards and so on.

I was about the make the exact same thread (well sorta).

What i wanted to point out was that each class shouldnt start from the same begginer choice.
As in someone whos aspiring to go full on sorceror mode wont be forced to run around willy-nilly with a bolter (not that i hate bolters, they rock!)

But for someone who wants to go the path of the sorceror like myself, a different starting point is in order.
For instance some sort of a cultist of acolyte.

I was thinking we would start of with something a bit weaker like a lasgun with our other weapon set (think i recall them saying you will be able to change weapons) perhaps a dagger and some sort of an artifact/focus with which we can channel smaller feats of warp magic.

At that beginner point we are given taste of both sides we can "choose", both offensive magic like casting some fire or a bolt of energy, and defensive like dmg resistance buffs for allies and yourself and maybe blindness spells (like flash grenades in games like CS 1.6).

As we progress we choose what to focus on more (if not to dabble in a bit of both, never excelling in one), further influenced by the god we choose to worship (for instance Nurgle will have more of a domain over DoT's when it comes to damage while Tzeentch will be more direct dmg focused, same would go with support with Nurgle governing over sheer durability boosters while Tzeentch would infuse allies attacks with certain attributes).

Bottom of the line is, there should be allot of starting choices from which we can branch out, and in no point should we go about playing something that isnt preparing us for our role ahead (countless hours of jumping around with a raptor will not prepare me for a allot less mobile role of a sorceror).

I'be heard that there won't really be "progression" just the character itself getting better and your gear getting more powerful

Wonder if the final choice to become a daemon prince will be there? Too overpowered probably but that is technically the goal of pretty much all chaos warriors, to lose their vestiges of humanity and become immortal and all powerful.

Maybe a starter class for the tutorial, so that you get into the basics of your chosen race, and can experience a little of everything before you jump into the actual wars. The Space Marines would get Scouts, Chaos would get Cultists (they're in the process of becoming Traitor Marines, and the term 'Cultist' is used to differentiate from the Imperial Scouts), Eldar would get Guardians, and Orks would get smaller boyz.

After that, you get to choose from the basic classes of your faction, with the exception of a few special classes that are by lore more powerful and rare than standard characters (librarians, sorcerors, farseers, weirdboy; psykers fit this example perfectly). In these cases, they are limited to only those chosen by the War Council to wield these powers. The basic classes are interchangable at will, but the more you fight in a certain class, you get honor points and can become a veteran for that season, where you get a bonus for that class and cannot receive another bonus for another class while you're already a veteran of one class.

The War Council will be consisted of permanent classes; in terms of Space Marines, you would have the Chief Librarian, Master of the Forge, High Chaplain, and Chief Apothecary, who would be their respective classes without limit throughout the season, and are in charge of choosing who joins their class, and their assignments.

Disclaimer: this thought-process was based on the Space Marines, and may not integrate seamlessly with the other factions, except maybe Chaos.