Forum:Qn on Summoning , Atk Targets

I did read the things on summoning from the rulebook etc. But there are things I am still not clear about.

1.) Let say for synchro summon . I have a lv4 tuner and a lv4 non tuner monster on my side of the field. I would like to synchro summon stardust dragon . so may I know more details about the declaring of synchro summon ? Cause my opp said that he can activate spells an traps such as book of moon or even Treacherous Trap Hole to stop me from sychro summoning . But since summoning does not start a chain, you can only response to it am I right ? Which means my opp should only be able to activate spells/traps after I synchro summon it ? also what about Xyz summon ?

2.) What's the detail meaning of a successful summon ? When I synchro summon stardust dragon, my opp activate bottomless trap hole stardust is able to negate it ?

3. ) When I controlled only 2 Command Knight, my opp cannot declare a direct atk right since I have monster on my side of the field ? also what about Marauding Captain (They can attack your Life Points directly if they control a monster with an effect that allows it (Such as Rainbow Flower, Inaba White Rabbit, or a Toon Monster) so in this case the atk directly is only or also ?