How to know if the bike is running lean?

[Jakobi]

As above. Grab a pen and index your throttle grip against the body. You need to methodically work through the circuits.

Starting rich is the safest option, especially if you're concerned of being lean. Do some reading in the jetting threads and see what needles are suggested. You need to consider the year of the bike, the model of carb, your fuel, temp, elevation, and humidity. They all make a difference. Also be aware that the circuits overlap, and as such the main and particular needle need to be matched. Some needles offer more fuel towards WOT than others. Some provide more fuel off idle. You can have straight taper needles, dual taper, or triple tapers.

No one can give you a magic setup. Starting points, YES! but the tuning needs to be done by someone on the bike, using it in the way it intends to be used (there can be variables in what a particular rider requires too).

I have no experience with the older generation bikes, so can't really comment. The LTR needle was part of Les Tinius' (http://www.lt-racing.com/) kit. I don't think it's offered anymore but was a rebranded (possibly modified) straight taper needle. Some searching may show some results.

In regards to your question, in reality you should be able to tune the bike below 1/2 throttle quite easily even with the main jet not installed. At a 180 you may get some blubbering at WOT, but it's much easier to step the mains down as the final process. Work on getting the needle and clip position right. Then lean off the pilot circuit. Then the main. Finally, work in the area of the slide cutaway, needle diameter, and pilot to really fine tune the off idle and small throttle response if you're picky in those regards. Many aren't that particular.