For what I saw (I'm about to finish my second run) your starting party is balanced, but I guess it didn't fit you play style.
Since I don't know how you handle encounters I can only give you some directions:
Front row:
I highly reccomend a barbarian with Heavy Weapons, mid-late game it can quite litterarly one-shot weaker enemies. Drop a a couple of points in accuracy as you level and aim to heavy armor.
A fighter or another barbarian will be nice for the high hp and damage, you should aim to heavy armor on this one to.
The weapon skill for this one is up to you, just remember:
Heavy weapons= kind of slow, higher damage and more powerful charged attacks. At 5 point you can hold a 2 Handed weapon in one hand allowing to equip a shield.
Light Weapons= fairly quick, mid damage, can be dual-wielded (can attack fron both hands separately) and with enough points in Critical you can backstab enemies for x3 times the normal damage (backstab can crit).
You can choose a Knight if you prefer, but remember it focuses on defence so it won't do much damage early on.
Don't pick a front row rouge until you are a little more familiar with the game, in LoG 2 evasion is more difficult to stack so creating a dodge tank is not as easy as it was in LoG 1.
Back Row
Since you're a relatively new player I suggest to stick with the alchemist, since you can make a better use of firearms and, more importantly, can "duplicate" the Herbs inside its inventory.
Remember to pick a point in Alchemy early on and don't focus only on firearms, but choose another ranged weapon or you can make him melee from the back row with 2 points in Accuracy.
The caster is really up to you since the Wizard and the Battlemage are not that different, just remember that now some spells requires more than one magic school and some rune combinations has been changes so search for the magic scrolls.
Races
All races are viable so it entirely depends on how you want to play the game:
Minotaurs have a lot of health and strength plus the headhunter trait for more damage, making them really good for a barbarian or a fighter, but they have little dexterity and willpower meaning they dodge less, miss a little more and have less energy for charged attacks.
Lizardmen have more elemental defence, since they have a passive +25 to all and can have another +25 from a trait making them optimal knight or even barbarians. They can also pick a trait that make them regenerate faster and double the effet of potions on them.
Ratlings are odd, since the start with low strength and health, but are immune to diseases and can pick the Mutation trait wich makes them gain a +1 to a random attribute every time they level up, potentially making them at par or even superior to other races if you're lucky.
Insectoids are a more magic oriented race (but you can make out good tanks/damge dealers from them if you want) so they can be a good pick for a wizard or battlemage, just keep in mind that the have very little health so try to keep them away from enemies.
Humans are balanced, they don't excel in anything but they don't have any main weakness either. The have a passive + 10% to exp and can choose a trait for another +10%. I think humans can get 1 level more than other races by the end game, but I've not tested it.
On a final note: stay away from the farmer class until you learn a little more about the game.
Hope this will be useful, and sorry if there are some atroucios grammatical and spelling mistake but I'm not a native english and I wrote this on the fly