RealGM

Can a team do a sign and trade of a player and move other players in that deal?

Been told "probably" but the Apron puts limits which teams can accept such a trade.

My example would be- Say the Cavs or the Knicks like RFA Alex Len at X dollars. Could Len's SnT be included in a deal to either that included other Phoenix outgoing contracts?

Thanks in advance

Yes it is fine, as long as you meet all the other trade rules (matching salary, staying under the apron, etc.)

A good example of this is when Keith Bogans was signed and traded as part of the deal that brought the Nets Paul Pierce and Kevin Garnett.

You can even include more than one S&T in the same deal. The Iggy to GSW deal eventually involved 5 players, 3 teams and two S&T's (Iggy to GS and I believe Foye from Utah to Denver). It's just less likely in general as every S&T requires another party in the deal to agree.