ThePonyTheorist 
[@Incursor](/images/2846594#comment_10071447)
No worries! So, magic comes in three parts. You have the gas, which is charged by exposure to emotions. This charged gas reacts to contact or proximity to runes, reading the commands the runes program into it and creating that effect. Charged magic should still be visible without runes, but would behave more like a chemical / standard gas than 'magic' unless it hits a certain critical level of charge/density where it starts to write its own runes.
1. To be fair, a few other characters have shown themselves to be capable of short-range teleportation. These were all advanced mages (Twilight, Starlight, Cozy if you count the portal-aspect of her draining spell) - but multiple ponies have used it. It could be a close-guarded state secret, but as much as I doubt that in and of itself, i'd also state that Chrysalis was the ruler of a kingdom in her own right, which could have similarly discovered that spell. It can't be that hard, even the name of one of the spells 'imaginary' Starlight was telling to sunburst in Celestial Advice basically gives away what you may need to do - Spacium Flexibus. Folding space.
2. It's very possible that a blast of magic being sent out can be programmed to behave almost like a solid, which would look like a force field. As far as the mass it's carrying, it's possible that the molecule itself is EXTREMELY heavy, so magic is very dense. It's possible that the volume held in Twilight in the S4 finale was actively condensed simply by its nature as magic 'liking' to condense (the orb made by Celly, Luna and Cadance was many times the size of her body after all) - and when she fired out a beam of it, the density was reduced substantially to achieve the massive volumes we saw.
3. The range decreased as we can see from S9E25. Since the shards were fired out from the explosion, it's possible that there were simply none in range to inhibit their magic after Chrysalis' defeat.
4. Indeed. I think that processing is where the runes come into play - the properties are changed to some extent on contact.
No worries! So, magic comes in three parts. You have the gas, which is charged by exposure to emotions. This charged gas reacts to contact or proximity to runes, reading the commands the runes program into it and creating that effect. Charged magic should still be visible without runes, but would behave more like a chemical / standard gas than 'magic' unless it hits a certain critical level of charge/density where it starts to write its own runes.
1. To be fair, a few other characters have shown themselves to be capable of short-range teleportation. These were all advanced mages (Twilight, Starlight, Cozy if you count the portal-aspect of her draining spell) - but multiple ponies have used it. It could be a close-guarded state secret, but as much as I doubt that in and of itself, i'd also state that Chrysalis was the ruler of a kingdom in her own right, which could have similarly discovered that spell. It can't be that hard, even the name of one of the spells 'imaginary' Starlight was telling to sunburst in Celestial Advice basically gives away what you may need to do - Spacium Flexibus. Folding space.
2. It's very possible that a blast of magic being sent out can be programmed to behave almost like a solid, which would look like a force field. As far as the mass it's carrying, it's possible that the molecule itself is EXTREMELY heavy, so magic is very dense. It's possible that the volume held in Twilight in the S4 finale was actively condensed simply by its nature as magic 'liking' to condense (the orb made by Celly, Luna and Cadance was many times the size of her body after all) - and when she fired out a beam of it, the density was reduced substantially to achieve the massive volumes we saw.
3. The range decreased as we can see from S9E25. Since the shards were fired out from the explosion, it's possible that there were simply none in range to inhibit their magic after Chrysalis' defeat.
4. Indeed. I think that processing is where the runes come into play - the properties are changed to some extent on contact.