This is my latest Stalker build, I use it to give me heavy hitting power at all ranges, with tag to overcome ECM equipped mechs. First match I played in it I only got 160 damage because I got snipped, but this build has potential.
Interesting build. Certainly versatile. It is rather a hot build though. I think sustained engagements would leave you overheating a lot. I can see why you designed it like that. Most support builds have little in the way of back-up weaponry and are vulnerable when opponents close in under the LRM minimum range. The key word here is 'back-up'. For me, the way to look at a multi-role build is to have a primary role and a lesser secondary role, rather than trying to make it good at everything. With this in mind, I would recommend, initially at least, swapping a ton of SSRM ammo for another ton of AMS ammo. 100 round still gives you 25 salvoes for your SSRM2s and the extra ton of AMS ammo will be useful in the builds main role as a support mech. Also, as I have touched on already, heat could be a big issue for this build. I've played around with the build a bit and come up with a slight redesign. Downgrading the LRM20s to LRM15s means you can drop a ton of ammo but retain a decent number of salvoes (24 vs 22.5 originally). Tuning the engine down (just to an XL300) frees up some tonnage, which along with the smaller LRM packs allows you to downgrade to standard internal structure. This frees up your critical space to install a further 6 DHS. Heat efficiency is increased to 31%. Although the builds max. fire-power is reduced to 55, the maximum sustained DPS increases form 3.16 to 4.15. Armour is a ton lighter than the original build, but more than sufficient for a support mech. Its always tempting to try and build a 'mega mech', with enough fire-power to take out an entire lance single-handedly. Unfortunately, either heat efficiency, speed, armour protection or all three suffer in the process, resulting in a spectacular design on paper that cannot possibly deliver in the 'real' world. By throttling back a little, planning your builds role(s) and balancing fire-power, speed, heat efficiency and armour accordingly, you can produce a more functional mech. P.S. - Having just looked at my own STK-5S build, this post may come across as a little hypocritical, as the build has 2xMLas and 4xSSRM2 as back-up weapons to a pair of ERPPCs. I don't actively participate in MWO at the minute (my PC isn't behaving itself), but I understand that light mechs are quite the plague online, so I beefed up the short range fire-power accordingly.
Personally, I went even further than you and dropped to a pair of LRM10's along with the XL300. That gave me enough space for 4 LLas. Heat efficiency is a bit better, but still nothing to write home about. I dunno, I guess it's a different role, though. Mine's more about a bit of harassment with LRMs at long range, then solid killing power at 450m, yours is about staying away. I just don't think LRMs are good enough right now to really justify building a mech around them.