what've read up on a long time ago
4/4 Wind and Ice acc
but due to the new merit 2 group may want to place 1 or 2 in earth(supposedly one doesnt make much noticeable difference)
I agree with 4/4/2 Wind/Ice/Earth, but most RDMs I know went 5/5 Wind/Ice before the second category was released and never looked back. They're comfortable landing Slow(II) without any accuracy increase besides perhaps an Elemental Staff. I really like to stack as much MND as possible on Slow II, riding the accuracy tiers, due to the different calculations of self v. mob stat that the new spells use. I'll get to this in a moment.
As for the second category, there's a few ways to go about this, and it is dictated by your play style. I know you really like to solo mobs, and so two each in Bio/Slow/Para may be the way to go.
Consider that by any account, Slow (and Elegy, and Haste) are incredibly powerful in terms of reducing damage dealt to whoever is tanking, and Paralyze takes off a full attack round only when it takes effect. Slow(II) is always in effect.
There have been a number of tests done to figure out how the second tier of RDM enfeebles change effect caps, and the influence of MND and INT. It seems that not only do they raise the possible %effect (for Slow, attack speed decrease and for Paralyze, rounds effect processes) but also allow you to get similar results in terms of %effect as the first-tier spells with a lower self v. mob MND result. (Though this is more important for HNM, which you said you don't worry about.)
I went for:
Earth Magic Accuracy +6
Ice Magic Accuracy +12
Wind Magic Accuracy +12
Slow II level 3 (consider that this provides about +6 m.acc)
Paralyze II level 2 (providing about +4 m.acc)
Phalanx II level 1
I think that Bio and/or Dia are worthless unless you're going to fully merit them. The 30 seconds you get initially is not going to help much; it would just be a huge MP drain to keep it up that way.
I don't solo enough to make Bio III worthwhile, but if I did it would be a hard decision to trade off. That last merit level increases the spell by half again as much duration, whereas the third level of SlowII/ParaII is not a clear 33% increase. ApplePie reports that Bio III is great for the massive attack-down-effect even over and above the DoT. For soloing, that's a must. I might advise you to fully merit Bio III.
Paralyze, Slow, and Blind have the same effects as their tier I counterparts with only one merit. you need at least 2 merits into one to notice any big difference.
This is not correct. Even the first level of II enfeebles are far better than the original spells, as you can see here with Slow v. Slow II:
It should be clear that getting Slow II and Paralyze II to at least one level merited is very important.
Tier II is a tough decision. Wouldn't you like to merit all of it? Don't waste your merits on Paralyze II, though. Every RDM I know who has merited that says it is worthless because the accuracy is balls.
I've had Paralyze II land and then not have any effect, and I've had it hit for five of ten rounds on Suzaku. Better to at least have the first level of tier-II, in my opinion and experience, because you know that it has better innate accuracy and possible effect, and a better self v. mob MND calculation.