One of the older conventions of rose care is to cut way back on a one-cane wonder to force more new canes. It doesn't work. It's kinda like beating a sick child to make it stronger, IMHO. If you really want the rose to get stronger, what I do is dig it up and pot it in good potting soil and in a pot that is not too big for the root system (otherwise they're susceptible to root rot if the pot is too big). Then I baby it along and see if I can get it to revitalize. If it's only got one cane, it's because it's weak and not growing well. Pruning off what little top growth it has will only weaken it more. Vigorous plants respond to heavy pruning by growing more, but weak plants die. I'd wait til normal spring pruning time to prune back Mr. L. I find that fall pruning in my climate, at least, results in increased cane canker from exposing cut wood to wet winter weather. Yes wind whipping can be a problem but it's better to stake and tie in most cases. You can indeed prune into old gray wood, so long as you see a bud. I'd only do a third or half the canes that way at one pruning and wait for the next year to do the others. I have revitalized old improperly pruned roses that way, but that was in mild California with long growing seasons and gentle winters. I haven't tried it here.

Ani, leaves harbor pest eggs and disease spores. By removing the leaves you open the canes up so they can be sprayed with the Neem or a dormant oil spray. It really has nothing to do with hardiness or root growth, just the general health of the plant. Roses in our local climate start to drop their oldest leaves as a natural growth cycle. By removing the leaves, we're doing what nature is going to do for us anyway. The only spray I use in my garden is one round of Volck's Dormant Oil spray after I prune in January. When using any oil-based spray, the temperature has to be under 60F, including reflected heat coming off block walls, so it can be tough getting even one round sprayed. The dormant oil spray helps to suffocate eggs and spores and should only be sprayed when the roses have no leaves. Because I often have roses from other people's yards come through mine for raffles or trades, I'm also trying to keep a disease called San Jose Scale out of my garden. Some great nurseries to purchase roses from in the metro-Phoenix area are Berridges, 4600 block E Camelback, Bakers, 40th Str & Osborn and Harpers, Hayden, south of Thomas. These aren't the only nurseries, of course, but they're well-known for quality roses and knowledge of rose culture.

Well, for one thing, a hybrid lily is not technically "a flowering houseplant". That being said, purchased in bud in the spring (definitely in the spring here in the colder climes), they probably will bloom indoors then will go into their normal decline of turning yellow and dying back as yours is doing now. Lilies do best outdoors planted in the ground where they will go through their normal cycle of sprouting from the bulb, eventually setting buds and blooming out before going into their natural decline. They only bloom once a season. Lift the bulb(s) to check if there's any rot. If not, and the bulb is firm and looks otherwise healthy, plant outdoors at least 6" deep if that's still possible where you live - you don't mention your zone .

I agree with what everyone else has said. They are new and young plants can have smaller blooms. Also, in the summer heat they are always smaller and have fewer petals. I bet you see a change this fall. Don't over fertilize. Water well. When it cools off the blooms will get larger.