Also any way to get a dragon mount shy of asking my gm how I can get one.
Unless your getting one through leadership or reskinning something already existing, your going to have to ask your GM. Of course you were probably going to have to ask him about that sort of thing anyway.
should I always donate all my money to the church in hopes they gear me out or keep it and just tithe so I can afford my own gear.
You don't owe the church anything. Might want to talk to your GM about that because if he keeps giving you flavorful items and keeping you up to where you should be with magic items, it doesn't sound that bad at all if your fine with the lack of control, but if he doesn't plan to or isn't interested then your shortchanging yourself in a game that expects you to have a certain amount of gear to keep up.
3. There is a necromancy wizard in the party and prior to me creating this paladin he took control of a skeleton. For those who don't know skeletons are naturally evil but when he takes control and is no longer doing evil acts buy instead helping fight evil is it still evil and do I have to kill it according to my code?
You don't have to kill everything that's evil. That's overkill. There are evil people who don't even show up on the radar. As long as he has it under his control its pretty much an automaton he controls. There isn't anything in your code about having to slay all evil or all undead.
1. What kind of mount should I use since I'm a gnome I'm small land can use medium sized mounts, it seems my gm is open to letting me use any of the Druid animal companions.
Depends on your flavor. Gnomes are creatures of wild magic, so I can see a pretty outlandish mount. A gnome paladin riding an axe beak would be cool. If you want a flying mount, check out roc. in an aquatic game? Gnome on a walrus would turn a few heads. How about giraffe or giant weasel? How about a giant gecko?
Also any way to get a dragon mount shy of asking my gm how I can get one.
Dragonne from B3? If you want a real dragon, I don't know a way to get one. As a GM, if you found a dragon or drake egg, and had some good Animal Handling, and role played your ass off, I would probably allow you to take it as a mount when it got to medium size.
2. My god is iomedae and during the last quest towards the end I gave away all my food to beggars in a sewer later found the bad guy/ quest objective and turned him in. I returned to the church, who gave me the quest, and they requested I show my selflessness and donate the reward money to the church. I did and the church I turn gave me the inheritors light, a +1 longsword that sheds light like a torch when unsheathed. Sorry for the long explanation but should I always donate all my money to the church in hopes they gear me out or keep it and just tithe so I can afford my own gear.
Personally, as a GM, if a character donates to the church, their offering may or may not provoke a return gift. Tithing is a given, and part of the character. Giving more, most likely will gives benefit, but it may not be apparent right away. Depends on your GM. If the church will subsidize you by you giving more than your tithe, do so as long as they will support you, there is no mechanic for it, though.
3. There is a necromancy wizard in the party and prior to me creating this paladin he took control of a skeleton. For those who don't know skeletons are naturally evil but when he takes control and is no longer doing evil acts buy instead helping fight evil is it still evil and do I have to kill it according to my code?
As MrSin stated, the skeleton is an automaton under the necromancers control. It is a tool. You don't destroy the sword when it's owner uses it to kill. Yes, the creature is inherently evil, but unless your got is very strict against undead, which Iomedae isn't, as long as the necromancer uses the creature for non- evil purposes, you are in no moral grey ground. You may want to discuss with your GM.