More answers than questions this time?I am grateful to Epicure and Rossi for their answers.
Now here is my own position:
1. Q: Is spirituality compatible with modern scientific research?
A: Yes, as long as the person's spiritual disposition does not interfere with
his/her rational thinking, his/her honesty in methodological and technical
procedures and documentation of results, and his/her interpretation of
results. Spirituality in this case will have an influence on the motivation
of the researcher for a particular discipline or a specific research theme,
but the risk that it will interfere with the quality of the reserach is
comparable to the risk presented by financial support of research from private
enterprises or from state.
2. Q: Does spirituality interfere with the capacity to critical rational thinking?
A: No, if the conditions formulated in #1. are respected, i.e. the capacity
and readiness of the individal with a spiritual disposition to separate this
disposition and rational thinking
3. Q: Is spirituality necessary for religious orientation?
A: No. Religious orientation may be chosen on a purely rational basis or as a
means to reduce social and/or ethical conflicts in every-day life
4. Q: Is religion a technical substitute for lacking natural spirituality?
A: As a logical consequence of my answer to #3.: Yes, I am convinced that religion
may have this function, and that religious leaders consciously use and abuse
this element.
5. Q: Is spirituality compatible with atheism?
A: Yes, once again under the conditions described in #1. and #2. The conscious
self might decide to opt for atheism as an alternative to opting for a
religious orientation, and the spiritual disposition might be the
motivator to decide that way.

Now for Rossi's question on the importance of religion for liberal democracy:

My answer is clear: the history of modern democracies (e.g. the U.S.A.) have shown that religious orientations - and in particular multiple religious orientations, even those of sectarian character - might be helpful for the development of liberal democratic decision processes, for the simple reason that they can help people understand the impossibility to change and/or to homogenize personal religious feelings on a societal level, thus facilitating a dialogue "over the fences". In contrast to societies with heterogeneous religious communities, religious monopolies (e.g. Roman Catholicism or Islam) tend to heavily interfere with the development of liberal democratic structures.

This time, the answers seem to prevail over the questions raised. Hopefully to read more answers, and why not, more questions...

Osservatore Profano