Dear Sharon,
Wa alaikum assalam
Arguably, one of the best definitions of 'misbah' comes from verse 24:35 where God shares a likeness of His Light as a niche in which there is a lamp (misbah). God's light is undoubtedly radiant and also the source. Thus if the analogy is carried to verse 67:4, the lower heaven is then decked with 'lamps' which seemingly refers to any celestial body which is a source of light possibly referring to suns within various solar systems that exist within any particular galaxy.
There is no conflict with verse 15:18 as there is no mention of 'misbah' in this verse. The expression 'shihabun mubeen' can refer to any visible celestial object or phenomenon, which could be a comet, flame from the sun, or even a meteor / meteoroid of sorts. This is irrespective of whether they are the source of light or not.
Therefore in summary to answer your questions directly:
I was just wondering does bimaṣābīḥa mean
1. Something witch produces it's own light like stars and sun [Yes]
2. Something just glowing like the moon or meators witch doesn't have to produce its own light [No]
3. Can 67:5 mean anything glowing in the sky that does or doesn't produce it's own light or does it mean it has to because if yes then 67:5 can't mean meators and [Yes, verse 67:5 is most likely not a reference to meteors but an object that radiates its own light] what causes problems with 15:18 because it says we can see it from the naked eye on earth with out a telescope [15:18 has little to do with 67:5].
I hope this helps, God willing
Joseph