Welcome to R3E mate You've starting playing one of the best racing sims out there and with some patience and practise you'll start to see why so many of us feel that all other racing sims feel bland and lifeless after playing this great game. If you want to learn to enjoy the AI the first thing you need to do is learn to ignore 90% if what Nano says and try the advice of people like CheerfullyInsane and Christian. These guys will help you get on the right track. To be fair to Nano tho; as with any title there are a few issues with the AI but the AI in this game will still give you the best white knuckle racing ever. You've already come across one of the issues. The first chicane at Zolder is notorious, I'm pretty sure this problem is occurring because some of the programmed optional pathways are too liberal with the curbs so the AI feel they have a straighter "right of way" "quick way" through the chicane resulting in them not seeing/expecting your braking and sharper turns as you enter the chicane. The only solution is to be aware if there is AI baring down on you and give them some room until it's fixed Check out this post of mine that explains how I manage this chicane <HERE>. It's a great thread to read with lots of advise for those that are willing to listen to it Some car classes seem to have better AI then others. Best AI that I have found are in the GT1's, GT3's and WTCR series (In saying that I haven't spent a lot of time in other classes as I just love these cars and their AI). These three classes give you great racing once you find the correct AI strength. To prove Nano and his groupies wrong; I've even set the AI to 120% and started at the front and never had a problem except at the first chicane at Zolder. There are also a couple of tracks where the first lap first corner can be a bit of a shit fight but you soon learn where it's problem and can easily avoid it. My experience with the DTM 2015 however has always been a bit hit miss (and this is where I do agree with Nano) as the AI do occasionally ram me from behind! I have not found this to be an issue in the 3 classes I mentioned above. So do a search of the forums and you will find some good advise; ignore 90% of what Nano and his groupies say and try 100% of what the others say when they have tried to help them.
Silhouettes are great fun too. As for that matter the FRJs and BMW235i. Those two will really teach you how to run in a crowd since it's bloody well impossible to break away from the pack.
I've found Adaptive AI to be pretty good so far, but how do I determine at what level the Adaptive AI has currently set itself to? For example it would be good to know how far off I am from say 100% AI Strength.
That I don't know, the thing is it will be different for different circuits and cars... So for example I drive the gt3s a lot so I may be at 110 on suzuka for example, but in a formula car at zolder or whatever I may only be at 90. The beauty is that it sets itself so you get a good race even if you may not be so good at certain combinations. I rate it very highly now I've got going with it. Previously I was either running away from the pack or getting my ass handed to me when picking my own level.