I've had a look at the BX STC and would say that for what you're describing all of them including the 8' are a wee bit too heavy on the cast weight ratings, that'll cause casting problems with regular weight trout lures.
I mainly just fly fish these days but was reared on a spinning rods and spinning rod techniques in the north west highlands, mainly for trout but the sea too.
Huntersforge set up above looks the business for the hill lochs, a bubble and fly fisher
, but perhaps a little light for the sea, although I've seen salmon caught on similar.
IME a good all rounder is a medium action spinning rod with a cast weight of between 5g to 25g, that will handle 8g meps (the ideal lake/loch mep size for trout) and will handle short casting a 28g tobby, which is the standard size for salmon, and of course it'll cast everything in-between.
While 5g to 25g would be ideal, they're hard to find in multi piece or telescopic travel rods formats, so a good compromise is 10g to 30g, provided you're using light enough line that set up will still shoot an 8g mep a good distance, here's a couple for around the £50 mark, a multi piece and telescopic;
http://www.fishingmegastore.com/shimano-vengeance-stc-travel-rods~18114.html
https://www.anglingactive.co.uk/shimano-stc-exage-bx-mini-tele-spin.html (model 21M)
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Line weight and quality is perhaps the most important factor. I can't recommend Maxima line enough, it's great stuff. 6lb for still fresh water trout techniques, mep, bubble-and-fly, bubble-and-worm etc and 8lb for the sea (6 will do for mackerel if there's no barnacled snags), moving fresh water worming, casting 28g tobbys etc and worming on the bottom in still water.
Any heavier and casting distance is compromised, lighter and you risk snapping the line and leaving wildlife unfriendly mono lying around.
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Best mobile hill loch technique for summer, if there's a breeze and therefore a wave on the water; is the bubble and fly; (bubble half filled with water tied to the end of the line, with two or three fly bearing droppers off the line 18" to 2' apart back towards the rod) the technique is to cast "into the wind" (or fish with "the wind in your face", as the old guys would advise when we were young) and retrieve quite quickly, bigger the wind and wave the better and the faster the retrieve. Size 10 standard loch pattern flies work great.
This works well when the fish are high in the water column on hill lochs, from late spring through to the end of the season. If the breeze drops off you can spin with a mep (the old 8g Abu Droppin in a selection of colours black gold and silver covers the various light conditions, brighter the conditions darker the mep, darker conditions brighter the mep, it's the exact opposite for fly selection).
IMO, there's nothing better than being up the hill in fading light casting a bubble and flies into a wave and to taking fish.
Sorry for waffling on
