https://webfiles.uci.edu/lcoon/cbafaq/salarycap.htm#Q92 The trade season re-opened just about now. Teams typically don't make deals between the end of the season and draft night but Daryl is most likely already making preliminary phone calls.
June 28th at 7pm ET(6pm Houston time) cant find any info on the lottery date, but it is normally the third week of May(last year it was on May 17th)
Webber was traded for Richmond during this period. But take that 2 players for Bosh deal as an example, if something like that could happen it obviously wouldn't be discussed until after the playoffs anyways. Nobody makes deals at this time, everyone in play is on a beach.