The game will not be too complex. The table top game can be picked up and played with little to no effort. From there the effort to get really good increases. You can, if you wish, get into the different Houses and their histories, conflicts and old aggressions. This is pure gravy. These message boards are what they are... 60000 seagulls fighting over a dropped bag of french fries in the McDonalds parking lot, because the Dev team does not feed us very much at the moment.
As for the complexity of the game itself, I really see some good things being done. If they stick close to canon, Mechs will have a variety of roles to fill, based on mass, speed and weapon load. When combat starts the game turns into a balancing act between heat generated vs. heat dissipated. If you generate more heat than dissipated, your Mech loses effective movement, targeting and... in severe cases, can suffer ammunition explosions internally or Mechwarrior damage. This is really no different from any Mechwarrior game previously produced, but the Dev Team is, for what seems like the first time ever, going to stick to a simplified system that will be easy for the average gamer to understand... the system from the board game! [Shocking to read, I know!]
Let’s take the Commando, for example. If memory serves, the Mech has 10 heatsinks and a weapon load of 1 Medium Laser, 1 Short-range missile 4 pack [SRM 4] and 1 Short-range Missile 6 pack [SRM 6]. Medium lasers generate 3 heat when fired, SRM 4 packs also generate 3 heat when fired. The SRM 6 pack generates 4 heat when fired. If they stick close to movement heat generation, which I see no reason why they wouldn’t, walking generates 1 heat, running 2 and standing still generates 0 heat. So… given a standard combat ‘round’ or ‘turn’, the Commando would probably look something like this…
10 heatsinks available
Mech ran [+2] and fired a full salvo of weapons [3+3+4=10] for a total of 12 heat generated. The 10 available heatsinks would dissipate 10 of the 12 heat generated, leaving a +2 heat surplus.
Heat management is as simple as that in the board game, round to round. The player can either choose to push that limit, or slack off on weapon fire to offset that heat gain. Say firing both SRM packs the following turn after a run, generating 9 heat. The 10 available heatsinks would dissipate the 9 heat generated, and then reduce anything in the surplus range… dropping the overall heat surplus by 1 point, down to a net of +1.
As for a new player coming into this universe and feeling like they don't belong, I could draw a comparison to World of Warcraft. You can join the game and level up on your own [as a lone wolf], or you can join a Merc company or House and play with friends or new friends you meet along the way. It will come down to how you wish to play the game and how you feel comfortable.
Hope this little insight clears things up for you, and welcome aboard.