I don't think that there is some sort of rules that beginners should not trade for full time. If a beginner is confident and have that knowledge that how to trade then they can trade for the time they want.
Please take a look around, and feel free to .
Trading full time and in the case of a newbie, learning full time does not mean sacrificing your whole eight hours to trade. Traders rarely trade for that long so a newbie can still trade and retain his job. It doesn't really matter when he does that but the commitment plays a major role.I think nobody should leave his or her main job to learn or trade in Forex. Because there is no guaranty of earning profit. That's a newbie should no trade all the time along. It is better he may trade for some time only to understand the Forex market and then after getting some experience and knowledge he can do it as a part time job.