Ni hau ma Benny Lao shi, xie xie ni bang zhu wo, qing wen , wo xiang wen ni wenti

1) the usage of “liau” is it correct that the meaning of liau is “already” ? as I sometimes heard people said like that.
for ex:
a) I have already eaten, wo chi liau, is it the same as wo chi le

b) If I only say “already” could I say in pu tung hua “hau liau” ?

2) As I know that “here and there” are zhe li and na li" could we say" here and there" are “zhe pian and na pian?” as sometimes I heard people say like that, for eg: wo jai zhe pian yi jing liuk ge yek le

3) How to say 1 dollar 25 cent, because I dont know how to say cent in pu tung hua.

Is Mei yuan (American currency) as same as Mei ji?

Xie xie ni lao shi!