DNS SNDMAIL SQUID service in nonrootuser

Dear all

I am having Redhat 7.1, i am running DNS,Sendmail,samba and squid service. Problem is, all these services r running in root account. I am woundered this is very easy for hackers to gain root privilage. I am not familiar with any firewall. I want to run these service in non-root user. Later i will configure firewall. HOw corporates r running these services(in root a/c ??!!). Most of the time i will be in online also. Pls. give solution to me…