problem with shooty army is like that is:
1. depending on terrain and cover. Will you be able to aways catch enemy units in the open?
2. LOS, just because you have the firepower in the squad DOESNT mean you will have los to enemy units.
3. most of those weapons are pretty slow moving (6'') its hard to manuver to catch enemy units.
4. eldar codex is not designed for gunline armies. many other codices does it alot better. (tau, marines etc etc).
5. the heavy weapons are grouped. for example warwalkers in a squadron can only fire at ONE target. the guardians weapons is in a guardian squad, so if you fire your BL at somewhere far away, you are wasting all the cataput shots on a closer, and possibily more dangerous unit. Another example, at 1000 points many ork players have 3+ trucks, backed up later by solid core infantry. with your current build do you think you can stop all 3 trucks coming and charging almost instantly. Once combat has hit, u are missing the most advantageous parts of the eldar army, its CC element. therefore. You will be doomed.
6. guardian BS sucks.
Conclusion: Not a great idea. The guardians are extremely vulnerable to pie and indirect fire (thunderfire etc).
If it is for pure experiment it is possible, however it may not be as competitive as you may have hoped.
TKE's NTGU Brigade
Doomliger's anti-DEFEND avenger tactica.