In general what I've seen of 5th edition, is that Flamers, Melta, and Close Combat are essential. These main weapons are spammed pretty much in every list where they can, and where things like flamers can't be taken, high rate of fire weaponry is used (this is as opposed to the high ap weapons that were famed an edition ago).
So, due to the close-ranged nature of these kinds of weapons, and since objectives are far more important than before (and keeping Scoring Troops alive to capture them), transports and mechanized in general have become essential. This was also promoted by the major increases to durability that tanks took with the new damage table, and how easy the table is on passengers now.
What this means in the end for a really solid and competitive list is that Waveserpents are a must along with heavy skimmers like Falcons and Fire Prisms that can take Holofields. BL's on as many serpents as possible help to soften targets as you come in for the kill as well as suppress incoming AT fire. Then, Fire Dragons and Storm Guardians are a good source of both Flamers/Meltas, while Bladestorming Dire Avengers help with their massive amounts of shots. Finally, a tough Close Combat ensures that you'll be able to absorb enormous amounts of these incoming shots, while also breaking units they touch with the new combat res system. In general Warlocks are perfect for this since they wound everything on a 2+, destroy tanks with str 9 attacks, and have 4+ re-rollable (fortune) invulnerable saves. Second best to these is Striking Scorpions, but they are so far behind that it's a handicap.
Static elements tend to do poorly now-a-days, since they don't proactively attack objectives, and since our enemies are so much faster now (transports, run, Deepstrike, Outflank, etc...).
The problem you're going to face with your list is that your static elements are going to be far from your mobile element which will need to move out, sometimes across the board, to hit objectives. This combined with a lot of units with small numbers provides easy Kill Points for the enemy (in 'Ard Boyz, Elites/FA/and HS are all 2 KP's with Dedicated Transports counting as 1). Hawks, and Vypers especially will be instantly targeted to reap these points, while pretty much all of the enemies AT will focus on your Avatar (since HQ's yield 5 KP's, and you really can't hide him...).
The best I can say given what you have (I'm assuming this is it?), is that Waveserpents and Wraithlord NEED Bright Lances instead of any EML's. EML's should probably go on the Falcon so that it can move and still fire small blasts and things. Consolidate the Pathfinders into one unit so that they won't be easy pickings, and can actually cause some damage. Finally make the Warwalkers weapon load-outs either ALL Scatter Laser, or ALL EML's. Either one of those will cause significant problems for the enemy, or you can take the El Cheapo route and make them ALL Shuriken Cannons and Outflank them to mitigate the short range.
I hope this helps man.
Good Hunting,
-Stezerok
