Targeting the env_glows with lights would have only turned them off (assuming they had names). However, my Half-Life FGD does have Names for env_glows, so I suggest you update your FGD to the latest 3.5 beta version. Env_sprites will not change size (I don't think) as you move away; or maybe the behavior is all tied to the Render Mode anyway.

You could possibly:

• Make a custom sprite and have the sprite actually phase in an out opacity-wise itself, and use that sprite for the env_glow. Or...
• Set the Render FX of the env_glow (if your FGD has such a field) to that of "Slow Strobe" and hope it synchronizes with the lights. If not, turn both off then turn both on again at the same time.

 with env_sprites you just set the rendermode to glow and it does the fade/size effect.

I highly recommend not using point light entity effects - they tend to be irritating and epilepsy inducing.

If you must, then there is no easy way to make the glow fade in and out with the light's strobing, you could try timing it up with some fancy multi_manager sequence, but it's highly likely you won't be able to synch it right.

Sound to me like you've accidentally made it a light_spot instead of a normal light entity.  Light_spots are......well, spotlights!  That would explain why it only lights a surface below it.  Check this.