You can farm lanes with minions, but you have to be nearby to get EXP.  Just about everything else is true, although I'm not sure that just being nearby creeps when they die will get you anything unless your minions killed them.

Yeah, I am really interested in what the exact mechanics are and where they differ between XP and Gold. In the Strategy Forum I found this:

- Flags split xp to every allied DG in (short) range of a cap.  Portal Grunts split xp and gold per Micah below.  Minions give no xp or gold when killed.  Teams should split lanes to farm grunts and cap flags.   Minions are great because they reward your opponents nothing when they die but while alive can kill, and you never run out of them. 

III. Micro:

Per Micah (thanks for digging through the LUA for this stuff)

If a demigod and their army (ie: minions and summons) does 25% of the total damage done (not 25% of health, 25% of total damage done) to a reinforcement then when that reinforcement dies a bounty is split amongst all nearby demigods (not just the one who did the damage). Also, if a demigod or their army gets the killing blow on a reinforcement then the bounty for that reinforcement is split amongst nearby demigods.

If a demigod does 25% of damage but does not get the killing blow and is not nearby the gold is still split, but they don't get part of that split. If a demigod (or their army) gets a killing blow though, that demigod does get part of the bounty for the kill.

- so that means as long as one guy in a lane is farming his ally can be sitting back and chillaxing and he will still get the gold benefits.  (Doesn't really make sense to me but I didn't write the code)

- again per a conversation with Micah made after his clarification post - Grunts will not provide xp to their killer unless he is in range, so using your minions to farm xp only works if you are close by.

So, some things are still unclear to me:

- You do get XP for standing next to creeps when they die. I was under the impression that you get more when you 25%-Tag them or kill them yourself. A result of that would be that fighting close to your towers would be bad, because the towers kill some creeps before you can tag them. Is that correct?

- When you kill stuff without being in Range (Minions, Heavens Wrath), you do get gold, but no XP. True?

- When you are in a lane without having large AoE, it should be better to alternate between creeps with your attacks, then killing one after the other, in order to 25%-Tag more. Actually getting the killing blow has no advantage over just tagging the mob. Right?

Since none of this information is really documented at all, it would be amazing if we could have some sort of official response on this topic. Its the kind of thing that the community could spend months trying to work out, or one dev could explain properly in less than five minutes.

I know that people have checked out the code to find answers, but there is so much conflicting information out there that I don't know who to trust.

I would like to improve my skills and play on a competitve level at some point-- it's this kind of knowledge that great players have over good ones.

i.e., I know what works for me. I don't really know why it works.

Maybe we'll just have to wait for better sources of information to come up via legitimate fan sites.

I'll try and post a propper writeup on XP/Gold mechanics in the Strategy Forum later.

Done: http://demigod.wikia.com/wiki/XP_and_Gold_mechanics

So to clarify you have to be in range to recieve gold?

That would be really strange, can't see that anywhere.

kBrain:GetUnitsAroundPoint(categories.HERO, pos, radius, 'Ally')

is the relevant call which gets all "close by" heroes, so unless there is a bug in that regarding Oaks ward, it shouldn't happen. The function no longer is lua code though, as far as I can see, so can't dig in there further.

Yes, range is not relevant when you actually kill the unit yourself. I just checked, for mines the dmg is considered to be coming from Regulus himself, so for mine kills you can hang around wherever you want

Interestingly, Rooks Towers shouldnt count as killing for him as far as I can see, but I don't really think thats correct ...

I just tried ingame, you really don't get gold for the creeps your towers kill as Rook.

Yeah, I wonder if it might be worth it to get lvl 1 hammer slam, just to be able to tag a wave for you completely, as your towers are in fact actually denying you gold.