Ask some question about Dmarc

1. What's happen If email system can not check dns record dmarc ? as timeout...

2. v=DMARC1; p=none; sp=none; rua=mailto:email@domain.com; ruf=mailto:email@domain.com; fo=1  : with this record then when email system received email failed dkim or spf will send report ? and if email system not check dkim or spf then will not sent report to us ?

3. how to know who fake my domain send email to our customer ? use dmarc can know who ?