Okay sha1 is not hackable. If you are using pfs in your ipsec configuration your safe from any attacks. if in doubt run short IKE/IPSEC key-life but I would not personally be worried over sha1.
Now yes FC6.4 still supports md5/sha1 "only" , why that is a business question to FTNT. Strongsan and greenbow are great alternative for ipsec-clients.
I think one of the reason mobile-devices are not using top-notch encryption is due to the size of the processors in the phone and the vendor don't not want to overburden these devices. Just my wild guess.
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