2000 VW Beelte - Car smelt like antifreeze the day we bought it, 2 weeks ago. Had radiator flushed and tempature light came on after 4 or 5 days. Need a second opinion, could this possibly be a leak in the heater core or more severe such as thermostat, water pump and timing belt?

engine thermostat is not mention the parts you changed, replace it.
consider the head cylinder gasket, it causes overheats.
a/c is another system, not a part of the system of first.

Replace the radiator.

I believe you have a head gasket or cylinder head problem (cracked head or blown head gasket).. If it is the gasket, the intake and cylinder head must be removed and a new gasket installed.. If it is the head itself, in addition to what have just said, you will have to have the head repaired or get a reconditoned or new one. This is a major repair.

undoo radiator hoses flush with hose the radiator and the engine do this on both inlets and out lets

is there a question here? Haven't seen one so far

thats because it is leaking antifreeze into the cab through the heater core

have the fault codes read first
never ignore any light on the dash as they are there for a reason and not decoration

I think you mean you saw water vapor (some call it steam) not smoke.

You probably have a hose leaking (badly). If it's not a hose, your water pump shaft seal is probably kaput.

U'll need to bleed the system.

What do you mean "check the radiator"? Does the radiator not work or only work every other day? You could have a clog in the cooling system and it might be smart to get it flushed out.