ok number 1, decree of justice, I declare cycle paying 2W
Right, and this triggers an ability that will allow you to pay mana and put tokens into play. The stack looks like this:
{pay X to put X tokens into play}
{draw a card}
opponant passes priority back, I decide to draw my card, then pay 8 to make 8 soldiers.
First you make the decision to pay (8) and make 8 soldiers. This is a seperate ability from drawing a card. So if you and your opponent both pass priority, the top item resolves, you pay 8 and put 8 tokens into play and the stack is now:
{draw a card}
Now, opponent cast cunning wish for stifle then stifles the cycling. Does drawing the card, or paying the X mana to make soldiers pass priority where opponent can respond, or can he only respond to the initial declaration of cycling the card. I haven't played with decree in a long time so I'm not sure if I was right or not.
None of that passes priority. Again, when you announce cycling decree, this puts the draw a card ability on the stack and triggers the 'make tokens' ability. Before you receive priority again, the 'make tokens' ability is added to the stack. Now, you pass priority and your opponent gains it. He may now respond to the tokens trigger. If that resolves, you pass priority and he may now respond to the draw card trigger. He will get at least 2 opportunities to play spells before you complete cycling.
I have sphere of resistance in play, and tinker in hand. 3 mana available. Can you announce tinker, sacrifice the sphere as part of casting cost then pay the 3 mana for tinker. Or, is the sphere seen as in play when the spell was announced and I have to pay 1 additional mana regardless.
I had thought you could sac the sphere in order to avoid paying its cost, but it appears you cannot. According to rule 409 (playing spells and abilities), you announce the spell and place it on the stack. You then choose modes and name targets. Next you determine the total cost and lock it in. At this point, the sphere is still in play.
Next, you pay all costs which includes sacrificing the artifact. So by the time the sphere leaves play, its effect has already been applied.
another stupid type 1 question
opponant has goblin charlbelcher in play and lions eye diamond. I have active welder. opponant sacrifices LED and discards his hand. Can I respond to the trigger of discarding his hand
Discarding your hand is part of the activation cost of LED. There is no trigger to respond to.
with the golbin welder by welding out his goblin charlbelcher for an artifact that was discarded this way before LED gives him the 3 mana to activate the belcher?
Only if your opponent is not the brightest bulb in the bunch.
He has priority and activates the LED. This is a mana ability and does not use the stack so you cannot respond to it. He then announces that he is going to activate the charbelcher and passes priority. This is now your first chance to play spells or abilities.
But even if he took the mana and then passed priority to you, you are better off just passing it back. The stack should be empty and since both players passed you move the next phase and he burns for 3.

If you don't pass priority and activate the welder, he can always then activate the belcher in response to the welder. Basically, you'd have to playing vs my 4 year old who's never played the game before in order for this to work.