Consolidate irule

Ok, this is a very rough merge of the various rules and comes with no warranties! It does not take into consideration the order the rules are executed in as I don't have visibility of this. You could potentially merge into one iRule (using multiple HTTP_REQUEST events) and use a priority value that matches the order the iRules are applied in on the virtual server to ensure they are executed in the preferred order.

Anyway, I've stripped out a lot of the switch statements for datagroup lookups. I've had a quick scan through the logic and I don't think there are any conflicts, so I'd check before trying it out. Also I've not tested the syntax as I've just bashed this out in a text editor but it may give you some ideas:

when HTTP_REQUEST { 
    Rule 1
    if {[class match [string tolower [HTTP::host]] equals host-dg-1]} {
        if {[class match [string tolower [HTTP::uri]] starts_with uri-dg-1]} {
            HTTP::redirect "https://[HTTP::host]/en/homepage.html" 
        }
        if {[class match [string tolower [HTTP::uri]] contains uri-dg-2]} {
            set arcom_uri [substr "[string tolower [HTTP::uri]]" 1 "/"]
            if { ($qrcom_uri contains "-") || ($qrcom_uri equals "en") }{
                log local0. "NEW: $arcom_uri"
                HTTP::redirect "http://[HTTP::host]/$arcom_uri/discover.html"
            } else {
                set old_qrcom_uri [substr "[string tolower [HTTP::uri]]" 1 5]
                log local0. "OLD: $old_arcom_uri"
                HTTP::redirect "http://[HTTP::host]/$old_arcom_uri/destinations.page"
            }   
        }
    }

     Rule 2
    if {[class match [string tolower [HTTP::uri]] contains uri-dg-3]} {
        if {[string tolower [HTTP::host]] eq "xyz.com"}{
            HTTP::respond 301 Location "https://www.[HTTP::host][HTTP::uri]"  
        } else {
            HTTP::respond 302 "https://[HTTP::host][HTTP::uri]"   
        }
    }

    Rule 3
    if {[HTTP::header exists True-Client-IP]} {
        if {[HTTP::header exists X-Forwarded-For]}{
            HTTP::header remove X-Forwarded-For
            HTTP::header insert X-Forwarded-For [HTTP::header True-Client-IP]      
        } else {  
            HTTP::header insert X-Forwarded-For [HTTP::header True-Client-IP]      
        }
    } else {
        if {[HTTP::header exists X-Forwarded-For]}{
            HTTP::header remove X-Forwarded-For
            HTTP::header insert X-Forwarded-For [IP::client_addr]
        } else {  
            HTTP::header insert X-Forwarded-For [IP::client_addr]
        }           
    }

    Rule 4
    if { [HTTP::host] contains "abc.com" } {
        HTTP::redirect "https://www.xyz.com/en/Privilege-Club.html"
    } 
    if {([HTTP::host] equals "abc.ch") || ([HTTP::host] equals "www.abc.ch") } {
        HTTP::respond 301 Location "http://www.xyz.com/ch"
    }
    if { ([HTTP::host] equals "abc.ca") || ([HTTP::host] equals "www.abc.ca") } {
        HTTP::respond 301 Location "http://www.xyz.com/qa"
    }

    Rule 5
    if {([HTTP::uri] contains "credit-card-verification.page") || ([HTTP::uri] contains "facebook.page")} {
        HTTP::redirect "https://[HTTP::host][HTTP::uri]"
    }

}
`

Data group details:

ltm data-group internal /host-dg-1{
            records {
                [www.xyz.com](//www.xyz.com) { }
                originwww.xyz.com { }
                xyz.com { }
            }
            type string
        }

`    ltm data-group internal /uri-dg-1{
        records {
            /en-12/ { }
            /en-34/ { }
            /en-56/ { }
            /en-78/ { }
            /content/global/aa/ { }
        }
        type string
    }

    ltm data-group internal /uri-dg-2{
        records {
            -country { }
            -country1 { }
            -country2 { }
            -country3 { }
            -country4 { }
            -country5 { }
            -country6 { }
            -country7 { }
            -country8 { }
            -country9 { }
            -country10 { }
            -country11 { }
            -country12 { }
            -country13 { }
            -country14 { }
            -country15 { }
            -country16 { }
            -country17 { }
            -country18 { }
            -country19 { }
            -country20 { }
        }
        type string
    }

ltm data-group internal /uri-dg-3{
    records {
        /en/ { }
        /cntent/ { }
        /apps/ { }
        /etc/ { }
        /ar/ { }
        /libs/ { }
        /bin/ { }
        /en- { }
    }
    type string
}