Some thoughts/suggestions:
-1 Rayquaza,
-1 Eelektrik,
+2 Thundurus. Of all your basic Poké, Thundurus (IMHO) is the preferred starter - a 2t Disaster Bolt is great! So, I''ll tend to work more of those in. I personally run 3 in my deck.
-2 N,
+2 Bianca. You may want to maximize these since you will be discarding cards (via Computer Search and Ultra Ball). These really help to replenish your hand without necessarily discarding resources (e.g., with Professor Juniper).
-1 Skyarrow Bridge,
-1 Tool Scrapper,
+1 Computer Search,
+1 Energy Retrieval (or Cilan). Computer Search is great to include in this deck because it helps to "thin out" your deck (to enhance your chances of drawing into the cards you need). There will be times when you must have an R energy to attach to Rayquaza EX; the Energy Retrieval or Cilan gives you that opportunity (nearly 100% of the times).
-1 Skyarrow Bridge,
-1 Tool Scrapper,
+1 R energy,
+1 L energy. A litle bit more energy is needed, IMHO. In today's current game format, you must be able to beat Blastoise-Keldo EX. This is arguably perhaps the "fastest" deck in the game today. So, I tend to lean my deck towards "speed;" i.e., speed to setup and attack. The Skyarrow Bridge does help at times; but I've found paying the 1/2 energy cost does not hurt me often enough to include it (especially since I will just Dynamotor the energy back onto one my benched Poké). Also, if you do setup quickly, you'll need not expose your Mewtwo EX (for example) too early; and more than likely, lose the Mewtwo EX "war" (most Blastoise-Keldeo EX decks run 2-3 Mewtwo EXs).
Further commentary based upon my playing style:
As you well know, your L Poké are all weak to F type attacks and there are 2 major F Poké being used: Terrakion and Landorus. One of the techs I include in my deck is Zapdos, a 120 HP, F resistant, L basic Poké whose 1st attack (for LCC energy cost) can snipe the opponent's bench for 50 damage. Its 2nd attack (for LLCC energy cost) can inflict 50x damage for each heads rolled (4x); so, you could KO an opponent's "big" HP Poké with Zapdos. Again, this is another possible attacker to help minimize your EXs exposure. You could drop 1 L energy and 1 R energy for 2 DC energy (you'll still have 8 L energy and 4 R energy). I'd suggest dropping the Random Receiver for this should you decide to test Zapdos (given all of the above revisions).
Another tech I've tested (and liked) is the Dual Draw Virizion, a 110 HP, W resistant, G basic Poké. This Poké not only helps with setup (with Dual Draw), but it also can KO Squirtle and Wartortle with its 2nd attack, Leaf Wallop. And after the initial Leaf Wallop which inflicts 40 damage, the 2nd+ Leaf Wallop (assuming it remains active) inflicts 80 damage! Now you can 1HKO Terrakion, Blastoise, and even a damaged Keldeo EX. You could drop 1 L energy and 1 R energy for 2 G energy (you'll still have 8 L energy and 4 R energy).
If the metagame in your area includes a lot of Tornadus EX decks, then having 3 Thundurus and a Zapdos in your deck may be preferred. On the other hand, if Blastoise-Keldeo EX decks are popular there (which I assume they are), consider including Virizion (drives opponents a little nuts at times - lol). Even if you played 2 Thundurus and 2 Virizion, that would not be that bad. (You may want to play Cilan over Energy Retrieval in the split starter situation since you'll have 3 different energy types.)
Either Thundurus or Virizion start prevents the t1 donk and gives you more attack options. Keep in mind that an opponent playing a Safeguard Sigilyph does not impact you much either with more non-EX attacking Poké.
Lastly - playtest, playtest, playtest! Find the combo options you like most!
Hope these comments help.
