At how many miles should I replace the timing belt and water pump?

You didn't answer my question about when I need to change the water pump and timing chain

well,i answered 1/2 of it,well maybe almost 1/2?change the water pump when it starts LEAKING or giving you trouble, Water Pump is driven off the accessory belt.don't worry to much about the timing chain,NO service required.should last the life of the engine!> keep you oil changed<. only if the chain rattles or starts making a slapping noise,then it would need serviced.the only ford that gives trouble with the chains(3) of them is the 4.0L SOHC engine in the Explorer,Sport Trac,and a couple others from the 90's up into 2010 or so.gotta pull the engine OUT if they want it fixed,$4000.00-$6000.00 to fix it? it's cheaper to buy a used engine.but,anyways,you will be ok with the Focus.my son bought a new one 2 years ago,no problems so far.good luck with yours.Oh,i have a 2000 F150 4.6L with chains,got 310,500 miles on it now,same chains from the factory!!

Thank you for your help. I am very greatful for this knowledge

you're welcome.