There are two kinds of "mirror" writing. One way has both hands writing the exact same characters at the same time. True mirror will create mirror images of all characters. Since your left is your dominant hand, natural writing with your right hand would "want" to be backwards, so you'd have to make a small conscious push to form letters properly when you write with your right hand.
My mom couldn't comfortably write without the paper upside down & she didn't have the typical lefty wrist bend. Lefties bend their wrists, so they can see what they've written as they go along. It's a symptom of our writing going left to right. If our text was right to left, you'd prolly see hand, wrist positions reversed, though cultures with text reading right to left have another hand position, where the hand is held below the writing in process. Our culture has a heavy bias against lefties.
I think reading upside down is a skill people can learn, as I can read upside down too. I could be wrong though, as I also have an aptitude for recognizing patterns & conceptualizing what things look like when they're rotated.
Can fold tongue, flip tongue, strangle myself with tongue.. can touch base of nose, but not the tip..
Most of us can't do any or many of those things. If you took a class where this topic was part of the curriculum, your teacher would love to have you in their class, as you'd be able to demonstrate things a lot of people have never seen. I think my friend's teacher asked her if she'd come back to show her skill to another class he was teaching. lol
Rolling "R's" is related to language learning. Babies babble in the language they hear, meaning they practice all of the sounds in their native language, before they ever say their first word. My lisp may have been learned, not hardwired, though I have that improper swallow too, which argues against it, as does my brother's lack of the same problem. My area has a strong "Low German" lean in it's American English, which means most of us have no problem doing the German "SCHL" sound combination. People from other areas will pronounce it as "SL". Because Low German predominates here, we don't learn the High German "CH" sound. The Low German pronunciation for "Ich" (means I, as in I did blah, blah, blah) is like "ISH" & High German "Ich" is in a sound I can't describe using any English word. Anyways, you were exposed to enough of that rolled R when you were an infant to have had it added to your baby babble. The rolled "R" is present in other languages, but less pronounced, which is prolly where & how you acquired it.
Raising temperature in the hands is a holistic treatment for migraine headaches & can be taught. Biofeedback is involved & has to do with intentionally changing your internal blood flow enough to offer some relief for the headache. It may work through the placebo affect, though the biofeedback for migraines should also be beneficial for all other kinds of headaches if that was the case & I've never seen it advocated as a strategy for them.
I could never, ever pull off a purrr. I've read that cat's talk to each other in their prt language & their meow is for communicating with us.
I started out writing lefty upside down..
In my freshman year I taught myself to write with my hand below and perpendicular to the line of text... with the paper at a slight "lefty" angle..
Calligraphy is probably the most difficult for me, as the calligraphic tips are made for right-handed people.. ( there are lefty tips available, but they are clumsy and only frustrate me.. )
Reading:
I sat "across" from my mother when she read to me.. That was the way I learned the words.. upside down.. wasn't planned..
I actually had to re-learn right side up..
I could read before I entered school.. ( My snotty little sister, too.. she was always trying to out-do me.. )
( typical sibling rivalry.. )
I was reading something like 4th grade level in the 1st grade.. 8th grade level in the 4th grade..
By the time I was 12 I had read the entire Bible, twice, Bullfinch's Mythology, Ulysses, The Odyssey, Darwin's "Voyage of the Beagle", Everything I could find of Science Fiction writers like Van Vogt, Heinlein, Asimov, Norton, "Doc" Smith, Western Novels like "The Plainsman", and novels by Louis LaMore, The Cisco Kid, etc..
My father was a heavy reader, and we had the Harvard Collection in the house, as well as tons of science fiction..
I was so familiar with basic story line and plot I could read the first and last 3 or 4 pages of any book, and a half-dozen pages in the middle at random, and write a book report that would get me an "A".. ( most popular literature is trash.. but you probably know that.. LOL )
I thought I read somewhere that the rolling "r" was one of those things some can do and some can't.. May be mistaken..
As to possible ancestral influence, yes, a possibility.. ( Irish, English, Scots, German )
Scottish alone would contribute the linguistic history for the rolling "r"..
High german "ich".. Yeah.. no need to describe it.. I know what you mean.. it's in the back of the throat.. ( glottal stop? )
Biofeedback:
Science Fiction again.. Between that, (Witches of Karres ) and explanations from the father figure, I had a basic grasp of ESP, telepathy, teleportation, telekinesis, etc., by the time I was 10..
I had read accounts of supposed levitation, etc..( FATE magazine )
It was a simple matter to extrapolate from those accounts of mysticism, yogas, etc., to taking matters into my own hands and attempting to control my body..
That's including sitting out in the snow, lotus position, practically naked, to see if I could control my body temperature.. I eventually decided to start "small" and succeeded with changing hand temperature.. never managed to survive the night in a blizzard with nothing but a loin cloth..
Purring:
Like I said, I was never able to accomplish it again..
Paradise Lost..
Rolling your r's also is related to the shape of your soft palette.
Although I'm predominantly Scots-Irish, it is nearly impossible for me to speak "Q Celtic".
I am genetically a throwback to the Welsh part of the family. [ie, I look more like my 5th cousins than I do my own parents and no one in my immediate family has green eyes but the 5th cousins and great-great aunts and uncles do]
I can speak "P Celtic" quite easily.
In general, the Q-Celts were "long-headed" whilst the P-Celts were "round headed" and the shape of the soft palette dictated the dialect.
Linguists believe that the difference in anatomy is what caused the "spin off" of P-Celtic to begin with.
All the hard glottal stops of Q Celtic consonants "gh" and "ch" were replaced by easier to pronounce "p's" and "b's", for example.
"Mac" became "Mab" or "Map" instead.