Question re: Multiple Enchantment Effects, Obstacle and Antecedents

I’m a little confused how adding multiple effects to an enchantment works. Under “Basic Enchantment Effects”, it says that multiple effects can be combined in a single enchantment. A few questions:

[li]Do you just add the cost of the effects into the Enchanting obstacle?
[/li][li]Assuming that the answer to 1) is yes, how do you handle different values for target, duration, etc.? Do both values get added on?
[/li][li]Assuming that 2) is true, does that mean you should add the duration, target, etc. separately for each effect, even if they have the same value (e.g., 2 effects that both affect a single target adds +1Ob for each effect)?
[/li][li]How do multiple effects work with antecedents? When you gather an antecedent you have to choose a particular effect for it. Does this mean that you can designate it to be used for, for example, “+1D to Sword and +1 to Power for the wielder”, and it can only be used for that, or do you need to use separate antecedents for each effect?