Could somebody who has used the PSR-740 and has a lot of patience please answer the following Q's for me?

I bought the 740 after three years of loving the 510. But so far I'm finding the 740 very hard to deal with. The main thing is Registration Memory -- I used to love hitting "record" and then being able to change the settings DURING RECORDING with the touch of a button. On the 740, the registration memory is inexplicably disabled during recording.

Secondly, there seems to be but two options in recording -- either record all the same instrumentation all the way through a song, or add each instrument one by one. Since I rarely use the same instruments throughout an entire arrangement, it looks like I'll have to add them individually... but then the keyboard requires me to punch in the chord changes ALL OVER AGAIN instead of following the original ones... in short, A PAIN.

Also, say I want a two-measure piano intro accompaniment, and then have the string accompaniment kick in on the third measure. So I record two measures of piano, hit stop, then try to pick up with measure #3 using piano & string accompaniment -- the keyboard WON'T LET ME. As far as it's concerned, the song ends with measure #2. Does this mean I have to record piano all the way through to the end (without mistakes, by the way, since the editing function doesn't work on accompaniment, only on the melody tracks), then come back and record the strings beginning with measure #3? This seems like a big undertaking, and again the 510 was much simpler in this area.

This is just the tip of the iceburg. The recording process just isn't user-friendly at all on the 740, and I'm thinking about getting my money back unless someone can tell me where I'm making a mistake.

Thanks...