Is any of the dollar DLC for this game worth buying?
The level cap packs are only there if you really, REALLY enjoy the combat and want some postgame.
The three characters are pretty good. Histoire is locked till Chapter 7 but is a good magical support. Plutia is basically a better Compa that has tons of magic damage. Peashy is similar but as more of a physical glass canon type. Both Peashy and Plutia can transform so they're powerful.
The tutorials and help touched on some of this, briefly, but I feel I am missing huge parts of what the heck is going on!!!
Anyone got a decent primer or idiots guide to this game?, or do I just keep on grinding through leveling up until I can beat the boss?
Calm down, it's a bit overwhelming but I'll and go through the ropes here. I hope this giant wall of text helps.
Stats: STR is physical damage, INT is magical damage (generally stronger). VIT is physical defense, MEN is magical defense. AGI is speed and evasion. TEC is accuracy. LCK is mainly for crit rate, but also a minor boost to accuracy, evasion and escape chance from battles.
CPUs are basically the console representative characters. Their strongest feature is HDD, basically it's a large stat boost you can use in combat at a onetime cost of SP. There's generally no reason not to always be in HDD during boss fights. Less so during exploration and random battles as the SP cost/usage gets too expensive.
Other characters compete with CPUs by virtue of their unique skills or raw stats.
The turn order is a bit confusing. It's determined by AGI. Basically, the turn order displayed in the top right corner only corresponds to what would happen if you used a single basic attack, and not full combos, so at times it's not too useful.
Basically there's an invisible value to every action you take, and what you do on a turn determines when that character's next turn will be up. So, for example, Defending has a small value and usually will get that character another turn pretty quickly. Full combos or using items however will take a bit longer, and so on.
The EXE Gauge. For now, you mostly want to fill it up so you can use EXE Finishers. These are basically free extra attacks at the end of a combo. Make sure you've got them assigned. Later on, you'll be able to consume the gauge(like SP) to do some powerful attacks.
I'm not sure what's so confusing about items and equipment but I'll try. Some items are percentage based, and others have more flat numbers. For most of the game you'll generally favor the latter, until you have enough HP/SP that the percentage based items become better. The item Hero Drink is particularly good though.
Everyone gets a weapon, defensive item, accessory slot and a disk slot. For this section of the game, you will really want the Life Ring accessories, as they considerably boost your HP (and thus the amount healed by percentage based healing). Otherwise, you usually just want the newest stuff you find in shops, or the things with the highest numbers.
Disks are basically a special customizable accessory. You will find various chips from fights, chests and exploration. You will find disks from plot progression, bosses and beating special enemies. Now here's how it goes: there are three classes of chips, with different types of buffs and powerups, and there are 5 levels of power for each chip class. Disks can only contain specific types of chips though.
So, a disk with a blue 3 slot and a red 4 slot can contain blue chips from levels 1 to 3, and red slots from level 1 to 4, but cannot contain yellow chips, or level 5 red chips for example. You'll want to customize disks to fit whatever current situation you're facing. It's mostly free and easy to use.
Finally, Crafting, or rather the Plan system. You have a limited amount of space called MBs, that expand as you go through the game. Using the plan system, you basically permanently expend these MBs for various purposes. In addition, each plan requires materials, found in dungeons or from fighting monsters and specific bosses. There are plans for items and equipments; once crafted, you can buy these items/equipment from shops. There are plans for game features, such as changing enemy difficulty and such, which you can then turn on and off at will. And there are dungeon plans.
Dungeon plans can flat out create a new bonus dungeon, change the contents of treasures in dungeons(which you'll sometimes need for materials), or spawn special new enemies/bosses. These new bosses are what usually drop different types of disks for you(or rather Medals, that you can exchange for disks at Planeptune).
TL;DR Cliffnotes Version:
Hopefully that wasn't too confusing and might have helped. I don't like grinding but you can do that and a lot of people do. However, here's my personal suggestions.
-Make and use the Easier Enemies plan. There's no penalty for this, and you can switch the difficulty later. Chapter 2 is a notorious difficulty jump that never really happens again.
-Have everyone equipped with Life Rings. The HP boost is quite considerable at this point.
-Stock up on Life Fragments(these revive KO'd party members) and important items to use. They're invaluable.
-The bosses you're facing are mechs, and thus take less physical damage. They take more damage from electrical and magical attacks. If you've got any of those, equip and use them, but not to the detriment of your party composition.
-If you've got any chips that could help against mech/robot enemies, try and make some disks for those. Not so important but it could help.
-A note about your attacks. There are three important stats: Hit Count, Power and Guard Break Damage. The power displayed is the total damage done. However, Guard Break Damage is multiplied by Hit Count. So an attack that hits 3 times for 50 Guard Break Damage will actually do 150 total. Keep this in mind when selecting your Guard Breaking moves.