Starting out - tax nonsense

[theArtfuldodger]

Ok, I'm sure I've read a thread discussing this before, but how exactly does the IRD go about determining 'intention'? What kind of trading time-frame would an income/profit orientated 'trader' be buying/selling over? Is there a set standard, or is it determined on a case-by-case basis?

How would each of the following scenarios be classified (all being 'on average')?

I. Someone who buy/sells over a day? (this one's obvious - a trader for sure)

II. Someone who buys/sells over a week?

III. Over a month? (are we getting into 'investor' territory here? Or could this person still scrape by as a 'trader'?)

IV. 3 or 6 months

V. 1 Year? (I'm guessing an this individual would be unarguably an 'investor').

Stinks who something as subjective as 'intention' is assessed so objectively. Anyway, how else they gonna do it I suppose... Oh and all this is obviously for tax purposes =D

Thanks.

EDIT: I want to be trading enough to be a 'trader' (tax benefits), but not so much that I do anything stupid/risky, being as inexperienced as I am.

Another noob q: could I use the expenses incurred in 'trading' (brokerage, stationary etc) to offset the tax liability on TOTAL income i.e. - income from other sources (other than shares) too? Or can expenses only apply to the income that was earned while incurring them?

Also, are losses on trades tax-deductible?

Thanks.