Second tranche (NB current RwGPS route for the km references)
725 - 848: Route philosophy issue. From Milnthorpe (A6) you have chosen minor roads into Kendal (fine), but then the A6 all the way to Carlisle and the B7076/B7078 (old main road) which stays close / parallels M74 to Glasgow. If you were riding this in 8 days, I'd understand that choice, but you're not, and earlier in the route you've been 'wiggling around' eg in Cornwall. In England, consider two alternatives: either:
1) through the Lakes (left at Levens bridge and) through Bowness and then either:
a) Grasmere (A591/B5322) and up through Mungrisdale, or
b) Kirkstone Pass and Ullswater
and back roads to Carlisle, or
2) Lune valley (Halton, Kirkby Lonsdale, Tebay, Orton) and then cross to the Eden valley towards Carlisle (Maulds Meaburn, Temple Sowerby, Lazonby, Armathwaite)
In Scotland, I confess an antipathy to the road paralleling the M74: noise and lack of 'imagination'. Mercifully I've only 'had' to take it as far as Moffat (on LEL, after sunset Day 2).
1000: Having forced your way past Glasgow, Campsie Fells and Fintry Hills is a lovely choice.
Note SYHA hostels at Crianlarich and Glencoe
1155-1170: Try to choose the time you cycle the A82 south of Fort William: in a 1000 mile LEJOG, this was my least favourite stretch of road (I'd joined it at Corran, having crossed Loch Linnhe on the ferry).
1172: Immediately after Fort William, recommend get off the A82 left to Banavie (A830) and take the canal towpath - excellent surface - then right at Gairlochy up to the Commando Memorial above Spean Bridge. I see you've chosen the canal towpath which leads into Fort Augustus (when are 'they' going to Scottify these names, I wonder?)
I've stayed at South Laggan hostel (
@1204, S of Invergarry):
http://www.greatglenhostel.com/
1235: Applaud choice of going east of Loch Ness. There are options not to drop into Foyers.
1273: Option to cross Kessock Bridge (cycle path NCN1) and take road along north shore of Beauly Firth.
From Beauly, your route is (imo) the best.
After Thurso, consider taking in Dunnet Head, as the most northerly point of the British mainland.