1. Persons making connections by public transport from outlying areas to the pick-up points may have time to spare before and after their Scottish Express journeys. For example, one Monikie bus arrives at Whitehall Street, Dundee about 08.37.  As the Scottish Express service to Jedburgh (for example) does not leave Dundee (outside the Old Howff in Meadowside) until 09.43. How about breakfast at The Counting House, very nearby, at the top of Reform Street, from 9am. - only £2.00?
2. If you choose ANY SAILING trip (see below), or stop-over at a midway point you are recommended to tell the bus driver of your sailing or other plans and times, when you join the coach.
3. When visiting Jedburgh the coach terminates about 12.43 at the woollen mill shops, which is quite a bit from the town centre. If you cross the main road to the nearest bus stop you can get a Munro's bus number 68 at about 12.56 getting into Jedburgh Bus Station at 13.05 (using your pass). Return from the Bus Station at 14.05 on Munro service 51 (Galashiels) or at 14.10 by First Bus service 68. Ask off at the woollen mill shops. You might also wish to take the local bus to Galashiels and get picked-up their on the return coach journey, but this must be discussed with your coach driver beforehand.
4. All return times can be severely affected by traffic around Edinburgh, Perth, Dundee and other places - always allow for this.
5. Several services on the longer journeys do not return to Dundee until after the departure of the 17.28/17.38 bus to Monikie from Seagate Bus Station. The later service (at 20.00/20.10) passes Broughty Ferry Library at 20.21 and Monifieth at 20.29 and travellers might want to finish their day with a short visit to some of the food & drink facilities at one (or more?) of these places, and can be dropped-off at these points.
6. Who will be the first to go to Ayr on a Monday, stay locally, and return from Largs on the Friday? If YOU DO please let us know the details. Contact below.
7. Air travellers might be able to take advantage of of the stops at Glasgow and Prestwick Airports, for outward and inward flights, or even for a family 'send-off' allowing some time at the airport, but check out the arrangements thoroughly beforehand.
8. At Fort William the bus stops near the pier and you have from 11.34 (probably a bit later) until 15.00 at leisure. You may wish to to take a 90 minute boat trip (meals and facilities available) with Crannog Cruises, leaving at noon.  Alternatively, you may simply take the short return ferry trip for £2.40 to/from Camusnagaul, run by Highland Council leaving at at 13.10 with return journey leaving at 14.15, arriving at Fort William Pier before the next sailing at 15.00 - you may not be able to disembark but need to stay onboard the vessel for the return trip.
9. At Largs you will find a very good selection of shops and other facilities. One shop very well worth a visit is "The LargSest department store in the world!", Hastie of Largs at 109 Main Street, where you can buy anything you can think of (well, almost :^) 
   As an alternative to shopping you can take advantage of a short sailing to the Isle of Cumbrae by Calmac ferry (summer timetable HERE) and then by local bus to the town of Millport on the island.
10. You leave the coach (destined for Largs) at Wemyss Bay which is scheduled to stop at the ferry terminal at 11.10 with pick-up time of 15.15. You may wish to take the Calmac ferry to Rothesay on the Isle of Bute (summer timetable HERE), which leaves Wemyss Bay at 12.15 (arr. 12.50), and leaves Rothesay at 14.30 (arr. 15.05) but this has not been checked for availability or times, and you must advise the coach driver of your travel intentions.
11.  
12.  

Please share your tips and comments with other travellers, as a result of your experiences. Write to me.

Suggestions for add-ons to the trips?

222 - There is a twice-daily Citylink 973 from Dundee to Oban, which also has connections to/from Fort William. This can be used to create a "triangle" trip with the Oban-Fort William Citylink service.

223 - Can return via Perth by Stagecoach 24 to Ballinluig and change to the 23 (also for travel to Aberfeldy).

224 - Halbeath Parks Garage is I think what is known locally as Manor Kingdom, and it's on Service 19 (Ballingry - Dunfermline - Rosyth) every 10 minutes. Connections at Dunfermline for Stirling, Falkirk and beyond. Connections at Gyle for Waverly Travel Service 67 via Ratho Canal (currently on a short term contract).

225 - You asked (above) who would be the first to stay locally and come back from Largs? Service 585 runs from Ayr to Greenock along the coast every 30 minutes (20 minutes on summer school holidays, service 60/120 on Sundays).

226 - See 222. One could travel to Fort William, bus to Oban, then 17.00, service 973, all the way back to Dundee. Only problem being, it doesn't get back to Dundee until 21.00 doing that, i.e. missing all the Monikie buses.

227 - McGill's Bus Service operate various similar services to points in Glasgow, Renfrewshire & Inverclyde as "Smoothiecruisers", and these make it up as far as Callander. Their days of the week etc, vary, but there should be at least one coach going further west every afternoon in the summer. Details in the following panel with links to the timetables.

228 - There is an hourly-ish service number 4 back from the road end at Caithness Glass works (north of Perth) to Perth Mill Street, if anyone wanted to break (sic!) the day.

229 - Glasgow Airport - change for Arriva's hourly service 300 to Clydebank, as well as frequent services to Paisley centre.

230 - After a bit in Aberdeen, take a Stagecoach Bluebird 201 to Crathes Castle or Banchory, up to twice an hour. M W Nicoll service 105 departs Banchory Corsee Road at 14.05, Banchory High Street/Mount Street at 14.06, Crathes Castle main entrance 14.17, back to Stonehaven Barclay Street at 14.44, not too far to walk from the "chipper" for the bus back home again  at 15.23.