I'm about 2 hours in (Chapter 4) and have some questions if someone wouldn't mind indulging me.

- Once you 'join' characters so they get the performance boost when close to each other, are you free to change that at any time should you not like the combo or is it permenant?

- When there is two (or more) characters vs one does the lone attacked character suffer defense penalties? For example in other RPGs (Buldar's Gate) if your warrior and thief attack the same person, and the person counters the warrior, the thief gets to attack vs a much reduced defense. The thief also gets to backstab... FE seems to treat each attack as if that was only attack against said character. Not very realistic.

- I set the game to Easy since I'm a FE noob, but now I'm breezing through every battle without any character being at risk of death at all. It's still early in the game so will the battles get harder or can I switch mid-game to Normal or Hard or do I have to start a new game to goto a harder difficulty level?

Loving the game so far.

Btw, the first question is answered by one of the in-game tutorials on supports.

 WoW is right, if you have you skill level to SS, Micaiah can use Rexaura. 

Supports are based on the character's element.  For more information, you can look here.  In general, Avoid is pretty much the best of support bonuses and likewise, Earth is the best element in the game.  Two Earth element characters supporting each other become pretty unstoppable.  When pairing characters, you want to look at what each character's element offers.  If you're pairing someone with Leonardo, consider what would help Leonardo.  He's an archer which means he has low defense and high avoid.  Pair him with someone to boost his defense or increase his already high Avoid.

If you're only doing one playthrough... you should probably do Normal.  That will give you a real feeling for Fire Emblem and make you work a bit harder for your victories.

Also, the tutorials are selectable from one of the menus.  The game doesn't go out of its way to explain things to you like Fire Emblem 7 did. 

Thanks WoW that's a great help! Didn't realize that elements would affect a pairing. I'll have to start going through the tutorials without waiting for the game to prompt them.

Wish I could find a copy of FE 7, I'd have prefered to play that one first. If I see it somewhere I'll probably pick it up too.

I highly recommend Fire Emblem 7.  It has my favorite Fire Emblem cast and the first 10 chapters of the game are partial tutorials that explain pretty much everything to you.  I liked that a lot because it gives even new players a firm grasp on how to play with various game elements as they're slowly introduced.

Fire Emblem:RD has sold 500,000 in Japan+America.Way to go.

Let`s hope we have those Others numbers

I just finished mission 3-11. I´m playing on normal mode and so far and hadn´t any difficulties nor casualties, with the exception of the last chapters of part 1. Having finished PoR, I loaded my end file for RD but honestly I don´t know what bonuses I got, I assume though that some of the green stat bonuses that some of the Greil mercenaries have are due to this. I haven´t been using the battle save feature in order to keep units alive, but mainly to level up low-level units, do OHK with critical weapons, kill the leader instead of surviving for x turns or steal some items first I really want before killing the enemy.

My best units so far are mainly Greil mercenaries, specifically Ike, Soren, Mia, Shinon, Gatrie, Mist and Boyd, from the Daien units Nephenee, from Dawn Brigade Micaiah, Sothe and Nolan, from the Laguz Ranulf, Volug and Ulki, from the Crimean units Geoffrey, Marcia, Callil and Elincia, from the Heron Clan Reyson and finally from independent units Haar.

I just can´t wait to beat the Black Knight. During the Laguz Alliance crossing of Ribahn River my maxed out Ike (he had already reached lvl 20 Hero halfway through part 3) was able to deal to him 6 hp damage with a forged sword. I gave Ike the Nullify skill thinking it would remove the Black Knight´s +5 defense bonus of his Alondite, but I had forgotten about his Nihil skill, lol. I just hope that on the next encounter, giving Ike the Nihil skill will nullify all of the Black Knight´s skills, especially the deadly Eclipse.

Once I finish Radiant Dawn, I plan on replaying it on hard mode and try focussing on different units, especially a bit more Laguz. I know people don´t like using them expect for the big guns of royal caliber, but I´d like to show some more "sub-human" love :) I will also try to focus more on Edward, instead of Leonardo who ended up a disaster, as well as BEXP Jill a lot because we don´t get much opportunities using her.

Anyway, what´s your favorite FE? Mine are The Genealogy War (whatever it´s called) its mid-quel Thracia 776, which is also the hardest FE of all, and finally the GBA Fire Emblem Sacred Stones.

Ew.  You use the Laguz.  Bad choice!  ^_^

Nihil will nullify the Burger King's specials.

Why BEXP Jill at all? I took her to the End Game and never BEXP'ed her at all except for the last 3 levels of each tier.

My favorites are Blazing Swords and Radiant Dawn.  The newer ones have too many features I really like having.