I would suggest using a skill calculator to estimate how many items to cook, since there's no "current xp" provided for me to go with. As you're asking about what to cook on a free server, I would suggest raw swordfish.
At level 98, it's impossible to burn these and it'll take approximately (using level 98's xp total -- 11,805,606 -- as a guideline) 8,778 swordies until 99. Again, since I'm not sure of your current XP in the skill, I cannot guarantee this is the precise number, so I'd really suggest using a calculator to get an exact quantity, which has been added in the "related links" section.
It really depends on what combat lvl you are but its prbably hill giants or moss giants
No, aboslutely not. Runescape has no level limit for F2P players, like WoW does. For example runescape has a total level cap which is lower for F2P players than it is for members, but that's not as big of a difference as being free to lvl 20, but having to pay to play to continue leveling, such as in World of Warcraft.
if you're p2p with high levels, I suggest Armored Zombies. If you're a f2p player, I recommend ankous or minotaurs in the security stronghold(barbarian stronghold).
Zezima is a level 132 or 123 because i know he is around 120-130 Zezima should be lvl 136 (p2p world due to summoning) and lvl 128 (f2p world as they won't count summoning in)
I'd recommend sword fish until 62 cooking then you can cook monk fish.
It is extrememly unlikely, i would not count on it. It is forbidden to ask for f2p updates on the forums and there are rarely f2p-only updates. Sorry
Around level 95 cooking, I would recommend.
lvl 79
The Answer will depend on your skill stats. Level 75 doesn't necessarily mean you can cut Yews or cook Swordies.
it would take 180,937 trout bear in mind you can only cook about 1000 fish per hour
elvarg is lvl. 83 in runescape.... seriosly
Account trading is specifically prohibited in the RuneScape rules.