I was also thinking of only allowing "bombs", or range 0 missiles, so you can still nuke the Mercurians. I'm not decided yet however, so please continue discussing the pro and cons, it helps me make up my mind.
Also, In case of missile ban, I'm going to let you spend any RP you invested on missile tech on any tech of your liking, so don't be afraid of researching them.
Ah. I actually saw the lack of bombardment as an advantage, but I think these LPs have shown I prefer a more skirmish type war than all or nothing blitzes. Of course, meson armed PDCs could help protect a planet by preventing ships from getting in range to launch their range 0 bombs.
I see two main problems with a lack of missiles:
a) Range is absolute. If outranged in a missile fight, you can maneuver to change the "effective" range (missiles can effectively fire farther at enemies in pursuit, for example), shoot down incoming missiles, or just wait for your opponent to run out of ammo. Against beam weapons none of these work; if the enemy beam weapons outrange you and they are at least as fast as you, you lose; you can never close the range and they'll gradually plink you down. Somewhat mitigated by fighters and gunboats, but not completely.
b) Almost impossible to deal with NPRs/precursors. Only a problem if we're going to eventually expand out of the system, but a strong block on that unless you want to just disable all opposition. Consider that precursors and NPRs can transit into the solar system and attack us. Star Swarm would still be workable, since they don't use missiles (though they'd be somewhat harder to handle without our own).
Of course, there are also the obvious advantages, like making a scenario where both sides wipe each other out much less likely.