Do I remove the plants from the yard garden and store them or let them stay planted outside?
In your region, it's ok to leave them in the ground year round.
I have been given a white ruffled cyclamen and its roots have come through the bottom of the pot. It has lovely flowers and more buds. Can I repot it now or do I have to wait until it stops flowering? Also, I have cyclamens in the garden which come up every year, so would it be okay to plant this one in the garden? If so, when is the best time to do that?
Yes, I would recommend wating for the blooming to stop before repotting the plant. Also, if this is one of the hardier types similar to what you have growing outdoors, then yes, it would be ok to plant it with them.
I've had this particular (indoor) Cyclamen plant for exactly 1 year now ... and despite the fact that it has no leaves at all, it is continuing to bloom with plenty of lovely flowers! Currently there are 27 flowers fully open, and a further 6 buds. Is this unusual?
Yes, that is very unusual. Since it's doing so well, I wouldn't change any of your cultural practices, but when the flowers start to fail, you might want to let it go dormant for a couple of months, then see if it will regrow leaves. https://www.gardeningknowhow.com/houseplants/cyclamen/cyclamen-care.htm
The plant leaves began to droop and when I touched, it everything came off. It is only the bowl of the plant left.
Did your cyclamen recently bloom? After a cyclamen blooms, it will go into a dormant state and the plant will look like it is dying. The leaves will turn yellow and drop off. So I hope that is what is happening here, that it's not dead, just dormant (sleeping). Once the leaves die, you should stop watering the plant and place it in a cool, somewhat dark place and let it sit for a few months.
For more information on the care of cyclamen, please visit the following link:
https://www.gardeningknowhow.com/houseplants/cyclamen/cyclamen-care.htm
Do cyclamen need deadheading? And, if so, how do you know when? I'm not sure about deadheading my cyclamen plant.
Usually the spent flower will flop over. You can part the leaves and cut out or snip with a small scissors the spent flower.
This helps the newer flowers emerge.
This applies to indoor and hardy outdoor plants.
https://www.gardeningknowhow.com/houseplants/cyclamen/cyclamen-care.htm
https://www.gardeningknowhow.com/houseplants/cyclamen/hardy-cyclamen-outdoors.htm
Is it possible to grow cyclamen plants from seeds?
You could but it would be difficult and time consuming to say the least. Most are only sold as plants. This article will help with growing them: https://www.gardeningknowhow.com/houseplants/cyclamen/cyclamen-care.htm
I have cyclamen which I got from a nursary and planted outside early summer. They died back after the first flowering but have now come back to life, one plant has flowers. Do I leave these plants out through the winter or bring them into the house? Thank you.
The tropical can only tolerate temps down to 40 F, while hardy can tolerate temps to -10 F. What variety you have and how cold it gets where you live will make a difference in whether you can grow them outside year round. For more information on its care, this article should help: https://www.gardeningknowhow.com/houseplants/cyclamen/cyclamen-care.htm