After several hours of usage my lines going outside to a/c unit will freeze.. ive also taken covers off unit in basement and have freezing on a-coil, restricting most if not ALL air flow into house... is this a low freon issue or am I facing more extensive problems?

Low freon, cloged air filter or faulty blower motor.

I'll add to Joshdta's list by including blocked or closed vents (especially returns), dirty evaporator coil, & a restrictive air filter.