Regarding what you say, I would not know how to respond, since I do not interact with other meditators, (except for a small Mahayana group once, v. briefly) my own experience has been very pleasant, but I work very hard, I get up v. early, early hours work best for me, do not travel much anymore, do not read or watch news or sports, (how I removed the major distractions). I got my hands on anything I could read on the jhanas, finally a Jewish scholar, Keren Arbel, her book on "Early Buddhist Meditation' combined with Expositor...That was it.The big problem with jhana is that it is easy to misrepresent what a jhana actually is, i mean stadistically speaking if 100 people think they are doing jhana, maybe 5 of those 100 are really following the instructions and experiencing what the Buddha was talking about. If those other 95 people are just doing "meditation" and not the rest of the path, maybe they are not practicing any of the path, and that is the
As for dangers I cannot see how this is possible. At least for a short length of time, the meditator has succeeded in being free of the hindrances, and reaching a state of calmness, even if he could not move on to the second jhana, besides, one can accomplish much thru first jhana alone MN 63. I have heard that folks with mental issues require a guide.
I agree, but that is not what I meant, during the meditation, no worries.About right speech vs right concentration, i would go that they are conjoined. If a person is practicing right concentration, at that moment he is practicing right speech, calming the verbal fabrication, some degree of noble silence and harmonious thinking. So its the whole pack.
It is the occasional other time, when one is not too mindful, that one tends to trip on speech.