Caring for Euonymus sieboldiana (spindle)

Hi, I have recently bought an established eonymus sieboldiana (in March) so the buds are just showing. Can anyone advise re the pruning—for instance, if I trim the elongated twigs back now (it is a bit untidy with crossing branches) will it remove the flowering/fruiting spurs. Does it flower on the end of the twigs and on new or old wood, that would help greatly.
I have also dug up a decent sized spindle tree from a friend's garden, it is about a foot high, but do not know the specific species, but it is deciduous. If I cut the top back hard, will it bud out from the trunk to create fresh branches or will it sprout from the base?
Many thanks for whatever advice you can give re this species.