Sorry for delay, was busy breaking things at work. I am able to tweak further Jeff's scene to get more details in sim. But let me first answer your questions.
1.At what scale should i sim with respect to world scale ….It is a very difficult question to answer, people say do this, do that but my personal opinion, whatever works for you, gives you right scale in final render, sim at optimal level on your hardware and setup (very imp), gives you dynamics you are looking for. Actual world scale sounds good to work on but in reality we all know how hard it become to work on it, although not always but in some situation or case, specially if you are dealing with huge sets, like your case. I am not aware about your scene scale so it is not easy to give you a number.
2. Do u actually use reseeding,i notice it takes a lot of space Reseeding is on by default and I have not touched it, so yes I am using it with default setting. I am not sure about disk space usage with it but it should not change drastically.
3. how do i get small detail that i can see in ur render.No short cut or fix method as each scene will be setup differently and lot of factors will influence the sim. Need lot of testing, trying and failing.
4.can u also share some of ur stats. Nothing great, sim for 240 frames took 2 hours that cost me approx 70 GB disk space and render took 26 hours with 12 GB RAM, OC i7 processor.
5.Will my base model on which am running the sim only can give more splashes flyingFor sure your base model is going to help a lot, specially if you have turns and up-downs, like your reference images. Some time if I am not getting good response from floor then I add dummy geos in between for collision, same I am doing in Jeff's scene.
6.How do you really start your shot ? do's and don't click on Houdini and jump in it
I am still learning and not sure the steps I am taking to get more details are right or not, but uploading some wip render samples from my tests. Not huge difference between these renders and I am still not satisfied with it, will work on it further. This week I faced some weird issues with my machine and while trying to fix it, I torn apart the files that I tweaked to get these renders. I will upload hip file in sometime, in case anyone want.