Dave de Vos
I also feel sensations in my tissue when training, which over time has gradually expanded from the outside of my lower arms to my torso. This is not very useful (that I know of) but I think it is a part of the process.
I think my connections are getting better and I think I'm making some progress in developing and using dantien, but again, this is very gradual. Sometimes in aikido I try to consciously use my body the way I train, but that's not easy. I guess I have to solo train more until it becomes like second nature. Also, I'm only 4 kyu in aikido (since last month) so aikido by itself is already quite a challenge.
just my opinion, but the connection you mention in the first sentence above is hugely important, huge! As it relates to what you said in the second in regards to using your body that way when you do aikido, you should be working to feel that sensation or connection in everything you do, before, during and after. IMO, the whole second nature stuff will never happen until you start feeling those things outside of solo exercises doing every day life stuff. So work what you have, what you can feel and just continue to build.