Tried to experiment in relaxed state with intention "to know what my body feels when i ask a question for yes/no response". Got two slightly different physical like feelings in the area of solar plexus.

This sounds like a good experiment not only to give a try to but to strengthen the connection.  It sounds like the kind of thing that definitely can strengthen when you practice regularly.  I also imagine your response doesn't have to only be a physical sensation.

And you may notice other things as well.

Are there other questions that can be answered with a yes or no that are more personally meaningful?

Try to think with your heart and feel with your brain 

One thing that i see often is in Bruce's work and other sources that i read is 'feeling'. Bruce mentions that once you know the feeling you experienced you can experience it again from memory later.

Feelings are expressed by hearth. But what could be wrong when i ask myself (my true center) a question and when i look into the hearth there is just silence. If there is something like belief that blocks my feelings or something that i cannot name then what can i do to change it?

So i want to ask, is here someone who understands feelings and can give an example how it works for him.

Soulmael,

Being in touch with your feelings and sense of using them, (like being an emotional or emotionally sensitive person) is a natural trait or instinct but I believe that anyone can learn and practice being more in touch with their feelings.  Even someone like me who is naturally an emotional person, I have to sometimes remember to give time to my emotional side.  I feel unbalanced when I have to focus on my logical, thinking, planning, doing side for long periods.  I’m much happier when life is more carefree and I have time to get lots of sleep, can daydream, and don’t have to be on a tight schedule. 

If you can eliminate things from your life and daily routine that can free up your schedule and give you time to yourself, quiet time, time to be meditative and reflective, and if you can just daydream and reminisce, those are good things to do and good practice for opening up the feeling side of you. 

I find that if I have too much noise and busy-ness in my routine then I’m feeling more sluggish and less in touch with my psychic and emotional side.  Sometimes I have to quit watching the news, watching TV, or spending time on my computer and just have more quiet time to myself doing things I don’t normally do.  Especially if I get outside in nature, or do spontaneous things I never really take the time for, it helps to open up my nonphysical senses.  Journaling, reading, or some other “me time” activity is also good. 

Sometimes just totally changing your routine or schedule or surroundings is a huge opener.  It’s why people need vacations just to get away from it all.  But I don’t like taking vacations where the schedule is filled with activities.  I’d much rather have a getaway vacation where I’m someplace quiet, relaxing, and peaceful.  I can imagine a nice place in the mountains, by a lake, fresh air, where I can just enjoy nature with no schedule or “to-do’s” whatsoever.     That would be nice!

Notice where in your body feelings originate? Follow the trace ....