Petrus LL question

[twistar]

Hey I'm new to these forums. I've just been browsing them a few days and I this is my first post. I've actually been solving the cube for a couple of years and I come back to it sporadically and now is one of those time. Right now my average is in the low 40's and I've been stuck there for a long time. One of the reasons i was stuck was because I didn't use typical block building techniques for the 2x2x2 but rather placed the corner and swung in each edge as was fit. I did this as a result of learning the Petrus method as a very beginner and I'm just now moving on to efficient block building which is really helping me.
But now to get onto the next beginners boundry that I've been carrying with me since I started to solve the cube; I still use the Petrus 3 look LL, permutate corners, orient corners, permutate edges. In fact I've only learned a couple more of the corner orienting algorithms this week and still have 1 to go. my F2L takes about 20-30 seconds and I'm able to do that LL in around 10-15 seconds depending on how familiar I am with the case. So I have a few questions about the LL
1. how much can it really improve my time when it feels like most of the slowness is coming from F2L (this is sort of a dumb question...)
2. with Petrus what is the preferred method for LL? is it OLL and then PLL? how many algorithms is PLL?
EDIT: or should I learn Petrus steps 5+6 and just do that and the 3 moves for permutating those final edges?
3. for the 3 corner rotation permutation I still use "Allan" (F2U'LR'F2RL'U'F2) and this move always takes me a really long time either because it's just a bad algorithm or I execute it badly but I'm wonder what some of the preferred algorithms are for this.
4. I would ask for help on 2x2 block building but I can tell that as I practice more I become more and more familiar with what to do and at this point I just really need practice

Sorry for the long post but I've allowed myself a lot of time for a long of questions to build up

 

[ErikJ]

I use OLL and PLL with Petrus F2L. COLL is pretty fast too but the recognition is slower.
OLL is only 7 algorithms for petrus and 21 for PLL.

your F2L can improve quite a bit. if you aren't color neutral yet, try it.

 

[h5n1]

For the edges instead of Allan I prefer to do (R U' R U R U R U' R' U R2) and for the clockwise edge case I do (L' U L'U' L' U' L' U L U L'2). Not sure if any of those are any more efficient. For the other cases I still do Bert and Arne just because I like the idea of giving algs names

 

[twistar]

thanks for the responses! I finally learned all the 7 OLL petrus algorithms (I should have done that a long time ago) and I'm going to start learning PLL. 21 algorithms isn't really that bad. also I think I found a nice substitute for Allan, or I guess it's also call U permutation. I'm working on becoming color neutral but it's pretty tough. I have a major aversion to yellow as being part of my 2x2x2 or 2x2x3 for some reason. I'm getting better though. Thanks again for the help!

 

[bixarrio]

Color Neutral is difficult for me too. With Petrus, I do whatever color feels right, but with Friedrich my cross is always white. I used to do the LL on Petrus with only Sune (or 4). That was before I decided to speed up. Unfortunately my F2L on Petrus is riddiculously slow, so I don't do Petrus anymore. What was nice about Petrus was that the first look of the 2 look OLL was done in step 4. Since I've learned Friedrich (and still is) I use my newly acquired OLL skills. Once I have all the OLLs memorized, I'll move to PLLs

 

[Lord Voldemort]

bixarrio - Learn PLL first. It's a smaller body of algorithms and so it'll improve results faster.

 

[bixarrio]

Thanks Lord Voldemort. I'll definitely do that.