We report on the pulse-to-pulse energy distributions and phase-resolvedmodulation properties for catalogued pulsars in the southern High TimeResolution Universe intermediate-latitude survey. We selected the 315pulsars detected in a single-pulse search of this survey, allowing alarge sample unbiased regarding any rotational parameters of neutronstars. We found that the energy distribution of many pulsars is welldescribed by a log-normal distribution, with few deviating from a smallrange in log-normal scale and location parameters. Some pulsarsexhibited multiple energy states corresponding to mode changes, andimplying that some observed {\lsquo}nulling{\rsquo} may actually be amode-change effect. PSR J1900-2600 was found to emit weakly in itspreviously identified {\lsquo}null{\rsquo} state. We found evidence foranother state-change effect in two pulsars, which show bimodality intheir nulling time-scales; that is, they switch between acontinuous-emission state and a single-pulse-emitting state. Largemodulation occurs in many pulsars across the full integrated profile,with increased sporadic bursts at leading and trailing sub-beam edges.Some of these high-energy outbursts may indicate the presence of{\lsquo}giant pulse{\rsquo} phenomena. We found no correlation withmodulation and pulsar period, age or other parameters. Finally, thedeviation of integrated pulse energy from its average value wasgenerally quite small, despite the significant phase-resolved modulationin some pulsars; we interpret this as tenuous evidence of energyregulation between distinct pulsar sub-beams.