An interesting query for potential optimisation...?

Just wanted to capture a query I was working on yesterday which was slightly 'interesting' in that it consists of a couple of layers of left outer joins and the joining with a derived aggregation table - and time permitting I'd like to revisit it because I'm sure it can be improved / optimised (but it is functionally correct).

select
  t1.tid,
  t1.alias as alias,
  t1.asset_label as asset_label,
  t1.terminal_id as terminal_id,
  t1.location_address as terminal_address,
  t1.last_updated as last_connection,
  t1.name as questionnaire_name,
  t1.questionnaire_id as questionnaire_id,
  t1.state as state,
  t1.value as publishing_state,
  response_stats.rcount as rcount,
  response_stats.last_response as last_response
from
  (select 
     t.id as tid,
     t.alias,
     t.asset_label,
     t.terminal_id,
     t.location_address,
     t.last_updated,
     qnr.name,
     qnr.id as questionnaire_id,
     qnr.status as state,
     at.value
   from terminal t
     left outer join
       (delivery_stats d,
        terminal_activity ta,
        questionnaire qnr,
        activity_type at)
     on 
       d.terminal_id = t.id
       and d.terminal_activity_id = ta.id
       and ta.questionnaire_id = qnr.id
       and ta.activity_type = at.id
       and qnr.status = "L"
     where
       t.id in(1, 20, 21, 22, 23)) as t1
left outer join
  (select
     tcq.terminal_id tid,
     tcq.questionnaire_id qid,
     count(*) rcount,
     max(uploaded_date) as last_response 
   from
     tcquestionnaire tcq
   group by
     tcq.terminal_id, tcq.questionnaire_id) as response_stats
on 
  t1.tid = response_stats.tid
  and t1.questionnaire_id = response_stats.qid;

Whilst technically correct - I'm not entirely satisfied of the need for the the top level left outer join which creates a full derived table rather than having a correlated sub-query / nested join that contains only the rows actually relevant to the result set. Something to think about perhaps, on a rainy (very rainy!?!) day :)

.