Can't be sure what's the question but from whatever I can make out I will try and answer. About speed, managed speed is given by FMC and selected you give it on FCU. Who will maintain? If ATHR is available and active it will maintain if not you move the thrust levers and maintain. OP CLB and OP DES are fixed thrust modes so in manual thrust you either put the levers in CLB or IDLE and once ALT* comes manage the speed with manual thrust. The trend arrow is a good guide for that.