fezzzywig
I'm the guy Nuance mentioned. I have a pair of STs with the standard OW2 dome tweeters and I use them in a 5 channel system. Originally, I used an older Denon AVR-1800 receiver (75 wpc bought new in 2000) combined with a 2-channel B&K EX 4420 amp (similar in power to your 7250 amp). The Denon worked both as a preamp and directly drove my NHT center and rear channel speakers. The B&K amp drove the STs. For 2 channel music, I was very happy with that arrangement. STs do very well with that kind of power, although they don't require it. The Denon/B&K combo you have now should be excellent with STs.
Last February, I replaced the Denon receiver with a used B&K AVR 507 receiver. Again, the receiver functions as a preamp driving the STs via the external 2-channel amp, and directly drives the center and rear channels. The extra power of the B&K receiver did help noticeably for the center speaker, and it's FM tuner is better than that of the Denon.
As far as your question about B&K's reputed warm sound. Now that I have the B&K receiver, I do notice that, but I never noticed it when I used the Denon receiver as a preamp with the separate B&K amp. Is it a problem with the STs? Not at all.
You might consider getting a used B&K HT preamp/processor. B&K has a new model (Ref 70) with all the latest video bells & whistles (very expensive), and because so many audiophiles seem to be unhappy without the newest and shiniest gear, there are now good deals on used B&K pre/pros. I found my B&K AVR 507 receiver that way on Audiogon. For you, I recommend the Ref 50 - I believe its audio sections are identical to the new model. It comes in the original Ref 50 version and the somewhat newer Ref 50 series II version. Depending on price, I'd pick the series II over the original version.
I'm in Gaithersburg, MD and if you ever come to the Washington, DC area, you're welcome to come listen.
Richard