Blacksmithing set, is it any good?

I read some of the gearing tips and such after I had spent 6 or 7 harmony and made the gear with the bought patterns. None of them have hit nor expertise on them. Are they even any good? Should I reforge the avoidance on them into hit/expertise? How much hit rating is required for hit cap? How much expertise rating is needed for the soft cap? Hard cap?

Thanks for any help

You mean the spiritguard 450 stuff? It's ok, I guess, if you can't afford higher item level gear and want to be geared to do heroic 5 mans fast. The 463 shield is particularly useful for a starting tank. Yes, reforge the avoidance to hit/expertise.

Personally, I crafted some 450 contender pvp gear to fill green geared slots when I first got to level 90. I figured the pvp stats (which are not on the item level budget) would help me farm honour from Tol Barad and Wintergrap, and so afford the honour gear (which is now a tasty 476 item level). I don't think it's got expertise, but it's got some hit. Nowadays, you'll want to kill that thunderforge chap and start learning the 458 crafted gladiator recipes.

I'm not sure on the ratings for caps - I just look at the percentage chance to hit L93 enemies on the character sheet. You want 7.5% hit. Strictly speaking, there's no soft/hard cap for expertise. At 15%, L93 mobs can't dodge or parry, so that's your target but you'll need epics to get there. At 7.5%, they can't dodge but can parry; it's got no strong special attraction for tanks (for dps, it's their hard cap), although the dps value of expertise does drop off behind haste beyond that point.

If you are starting off at Level 90 and I have 450 gear, I would not sweat trying to be capped against L93 bosses. 5 man mobs and bosses are lower level and you'll not have the item budget to get capped anyway. I'd go for a bit of hit/expertise (2.5% or 5%), then bulk upon stamina. The ghost iron dragonling is a great starter trinket to get 1800 rating for hit/expertise/haste, and you should be able to find an engineer who will make one for you (e.g. via AH) as its BoE.

As a starting off tank, I recommend forgoing the haste route. Mastery/stam is a far safer route and 600 mastery rating on top of the hit/exp in a Dargonling is really good, as Econ21 stated. I do not really care about the haste bandwagoners...I'm one of them but I do know that as a starting tank, survivalability is key and learning how to operate as a tank is as well. Haste is not a survivability stat, it's a DPS one. Sure, you get a bit higher uptime on SoTR, but that's not gonna make or break you, ESPECIALLY with very little haste. What is going to make or break you, is your ability to stay alive, and that's going to come from stamina and mastery.

You're gonna be behind the curve a bit and probably meeting some higher ilvl dps and with luck, healers as well who can just power heal you. However, you're also going to meet the opposite and you'll have trouble staying alive as your group struggles through. You'll also probably have people pulling mobs for you, etc. Just be ready to expect that.

Rating wise, 7.5% hit is 2210 hit rating and 15% exp is 5100. However, you do not need that much for 5 man heroics, 6% hit and 12% exp should be your goal. Even if you cannot reach the 12%, don't fret about it as 6/6 is substationally good enough.

However, now there is 458 craftable gear that will enable you to get some higher stats over the 450s.

I put together a set of it using Wowhead's compare feature with the 450 set showing some suggested reforges and enchants. This should get you heroic ready.
http://www.wowhead.com/compare?items=82969.0.0.0.0.0.0.0.122:82925.0.4427.0.0.0.0.0.122:82924.0.0.0.0.0.0.0.132:82921.0.0.0.0.0.0.0.122:82922.0.4431.0.0.0.0.0.132:82919.0.0.0.0.0.0.0.122:82923.0.4870.0.0.0.0.0.122:82920.0.4910.0.0.0.0.0.132:82926.0.0.0.76681.0.0.0.132:83802.0.0.0.0.0.0.0.122:77530.0.0.0.77545.77543.77542:83796.0.0.0.0.0.0.0.122:83796.0.0.0.0.0.0.0.122:90466.0.4445

I recently got another paladin to 90 who had something close to this gear set. Heroics weren't super easy by any means, but were fine with a good group following proper strats.