What you described about the multiple branches radiating around the trunk, just below where the trunk has been top cut, is a typical growth pattern for such drastic top pruning. All too often growers have already done such pruning to larger crape myrtles when they are shipped to the retail nurseries. Did your area get the recent days' hard freeze around the Easter holiday? If so the CM in question might have a lot of dead wood which needs to be pruned out. If such a freeze happened, watch the tree as its remaining buds leaf out again. Once the tree appears to be fully leafing out enough to look recovered from any winter or freeze damage; totally remove any trunks or branches which fail to releaf. Also from the trunks nearest your house, completely remove all the way to the trunk any branches in the canopy which you can clearly tell will grow to infringe on your roof. Throughout the following growing seasons feed the tree with slow release quality food, and after every week which fails to provide an inch of rain for the shrub, suppliment the tree with that much water. Over the summer let the tree bloom naturally, and do not prune off the resulting seeds in an effort to extend your bloom season to the first freeze of late fall or early winter. By letting the tree bloom by itself and by being patient if it seems to slow down in bloom presentation after the first bloom flush; the tree will be enabled to put forth effort into thickening its branches and developing its proper rooting perportions. After the tree goes dormant, depending on when temps drop low enough for that, consider the space which any branching from the trunks still invade your roof line. cut, at that time, each trunk, all the way down to the root ball, whose canopy clearly will grow to infringe on your roof line. Hopefully when you have accomplished all the above pruning you will end up with the best of either a one or three main leader trunks. Then, in early march of the next year, prune out again all brittle dead wood, brake off the remaining seed pods and their twigs. Then turn your focus onto any remaining radiating branches which are growing just beneath the previously described, chopped off trunks. Preserve only a flexible and clearly healthy branch which grows the most directly upward and toward the direction where you want the trunk to continue growing. Prune away any other branches which are growing around the trunk near the same level of the healthy upward growing branch you selected to retain. To repeat: the one branch you choose to keep growing off the end of such chopped off trunks should be the one out of the ratiating bunches which appeares to be growing most upright, and growing in the right direction for the retained branch to assume the role of developing into a continuation of the trunk. Hopefully each single branch you select to continue the remaining trunks are thick enough to survive the following winter freezes. If not you will need to wrap each and their tunks with cotton insulator wrap prior to each freeze. If the temps are forecast to drop down to a hard freeze than add bubble wrap around the cotton wrap. Just be sure to remove the plastic bubble wrap any time the temps rise back up above 33 F. degrees. The above advised action takes a lot of dilligent effort, so if you do not think the tree is worth the trouble, simply remove it, grind the stump and main roots and purchase a 10 to 15 gallon sized, 25 to 30 feet potential height grower Crape Myrtle which has not also already been such drastically top pruned-down by the grower. With any such new CM tree you plant in the area, make certain to plant it far enough from the house to prevent roof damage, and to also prune train it properly each year just as you first described above.

Definately do cut out at the base, all trunks in your CM that are blooming pink. Then be certain to pinch off any new growth that the roots of those cut off branches try to keep growing. If you keep the new growth pinched off then only those roots should suffer,and the white blooming branches should begin to experience an advantage, which helps them to prosper more. Unless it is just the lighting cast on the day you took that photo of the pink blooms, the pink blooming trunks might be a Biloxi Crape Myrtle. Those bubblegum pink blooms, in my opinion are a much nicer sight than some of the more pale easily washed out pinks that some CMs produce. Anyway I only tell you this to let your know that if you do like that particular pink color and would like to have a CM growing someplace else with that color, Than simply order or find at some local nursery a Biloxi Crape Myrtle that is already blooming and that you can confirm it really is a Biloxi Crape Myrtle.

@agardenstateof_mind I completely agree with you on the ubiquity of crepe myrtles. They're all over my state too. Unfortunately after researching for months, I've found no other tree that flowers as long, and can also handle all day zone 9b full sun. In Sacramento, from late April to early Oct, almost every day is over 90 degrees-and as high as 114-with no rain. All other trees I've considered flower a month at best. However, I'm totally open to any suggestions you have! I would love to have a spectacular specimen tree! I'm going to try to plant a Venus Dogwood and a Oxydendrum arboreum sourwood, though they'll likely get burned to crisps.

I think the sensitivity of crapes is being overstated a bit on this thread. They aren't that delicate depending on the cultivar. Anyone in a coastal area doesn't need to protect their crape at all. Rockman had a great point about the drainage. CMs hate wet feet. This may play a significant role in how well mine have done. I have very infertile sandy soil which is exactly what they like. Even though mine are getting quite large now, they were little once and they did just fine unprotected. I've had the Hopi CMs and the Acoma for about 12 years now and they have survived many New England winters. There were a few branches here and there that would die but the majority of top-growth has done just fine over the years. One observation I've made is that they have bloomed much better after they got larger than when they were little. I don't think the winters stunt them quite as badly now as when they were small. I haven't quite figured out the combination of environmental factors that is detrimental to CMs in this area. It's not just cold because it also gets cold in the South, too and these things are ubiquitous there. The cold doesn't last as long down there, though. New England has much more wind than the South. This could be a strongly contributing factor. The soil is certainly different. It snows there, too but not as much as here. The soil pH tends to be more alkaline in the South than here. I'm not sure if this really makes a difference. Basically, it's complicated. I'm not sure if there is a certain formula to follow for success.