The old joints are not necessarily bad  why donÂt you post a picture. It sounds from your description you may need more ventilation or light.

These plants can take a great deal of heat. I recently acquired some that had been in full sun for several years. They were burned, but after removing the foliage they were healthy, strong, plump, & without bugs. They will go in shade to prevent burning.

I water mine when the soil is dry. My soil is dry a couple of hours after watering, so my frequency is daily.

Instead of throwing the older cutting away, why not root it? Others have their preferred method, but I root mine in sand. If I under or over water it, it is more likely to take.

1. As they age it is normal for the older branches to become woody.

2. I dont know whether we are supposed to or not either so dont tell ANYONE. Miracle Grow moisture control with an extra handful of perlite thrown in!

3. Bright shade with a couple hours of morning sun. Water generously in the summer but alow them to approach dryness before watering again. Do not bake them they are not desert cacti. I dont know which side of the glass doors yours are on but by all means put them out under a tree if possible. Root the younger tips not the woody parts.

I find mine have done better with a lighter, fast draining soil - I usually mix african violet soil with perlite and orchid bark. Water when dry.

I agree that older plants get a bit woody - if the woody part is soft and crumbly, you have a problem.

Mine spend from the last frost to the first frost in a shady no-sun spot on my porch...then come inside, get a bit of morning sun in a south east window, and that's when they flower.