The powers are all over the place. Some seem really cool, like Magic Weapon and many of the Dailies. But most of them seem distinctly 'Controller'-y, while these guys are a supposed to be Leaders, right?
A couple of points.
First of all, as an arcane class, there will be a certain ammount of controller "flair" to the class.
Secondly, controllers and leaders are similar in a number of ways. Where a leader would give his party a boost in speed, extra movement and the like ... the controller would force movement on enemies, slow them or immobilize them. A controller would boost an allies defenses or to hit rolls or damage, while a controller would apply penalties to an enemies defenses or to hit rolls or give them vulnerability to certain damage types, etc. In some cases, the two effects are basically the same (i.e. giving an ally a bonus to hit or an enemy a penalty to defenses) but have subtle differences (a single ally with better AC would discourage any enemy from attacking it, but a single foe with a penalty to hit may have no good options to attack for the turn).
General reflections on the artificer class itself would be appreciated, too, as well as suggestions for building a halfway decent one that won't doom his party by occupying the Leader slot.
The clarification people have given on the healing infusion will hopefully help you out.
A big issue is to decide which way to go with the artificer in terms of ranged, melee and implement attacks. With the feat for using crossbows as implements, and the feat which allows light or heavy blades as implements, it's possible to have your implement and one type of weapon slot filled by a single item (all three attack types are covered by a dagger, drow heavy blade, or any blade with the enchantment that makes them heavy thrown weapons). However, with increased versatility, you get lower damage output, not to mention limiting your options for enchantments (on the other hand, you need fewer expertise feats and you don't have to have multiple magical implement/weapons). If you do go with multiple weapons/implements, I suggest taking a disembodied hand as an arcane familar ... it allows you to draw and stow weapons as free actions ... allowing the artificer to more easily swap between his crossbow, his melee weapon, his implement, alchemical weapons, etc ... (and the idea of someone carrying an assortment of weapons, and having say a robot hand to help pass him stuff just screams artificer to me).
Many of the extra stuff that artificers do is quite nice. Their ritual casting class features is nice to have as it helps to stretch the party's cash. Similarly, the ability to enable reuse of daily magic item powers can come in quite handy for certain items as well. The temp hit points tied to daily magic item use is comparable to the healing from spending an action point near an inspiring warlord. One big thing to consider, especially as I would guess a dwarf artificer may be a bit lower on to-hit and damage ... perhaps alchemial items would be a good investment. As an artificer, with the class specific feat, they are able to make alchemical items at a higher level, and since those items are single use, it would still be affordable to make items above your level. Those items have fixed attack and damage, which scales with level. Thus, those above your level would give you attacks that are probably better than your standard ones. Similarly, the daily attack powers which enhance weapons or armor may be a good way to go as well.
