Attacking with warhorse and domain progression questions...

[Angrygodofmilk]

First question, when I use a Ride check to "Attack with Warhorse", how many attacks can the warhorse bring to bear?

Second and third question, as a cleric spellcaster, if I take a prestige class that grants +1 level of divine spellcasting, does that increase my access to domain spells as well? What about domain powers?

 

[frankthedm]

First question, when I use a Ride check to "Attack with Warhorse", how many attacks can the warhorse bring to bear?

That depends. If you were next to the foe at the start of the round or only took a 5' adjustment, your mount could take the 'full attack' action, getting it's full compliment of attacks. Otherwise, the mount only gets to make one attack, unless it hase a special ability such as pounce.

Also, note that if you are wielding a reach weapon while mounted, you and your horse may be unable to attack the same foe.

 

[Maleketh]

Second and third question, as a cleric spellcaster, if I take a prestige class that grants +1 level of divine spellcasting, does that increase my access to domain spells as well? What about domain powers?

You'll continue to gain access to your domain spells. This is a function of your cleric spellcasting and is thus improved by your PrC.

Domain powers, however, are based on your cleric level, not your spellcasting level. Some PrCs might improve your domain abilities (Paragnostic Apostle comes to mind), but these are exceptions rather than the rule.