I am jumping in late on this thread but I thought I would add my 2 cents.
I am in a similar situation, scanning a family archive which spans many decades and various film types. I scanned a few thousand slides using a Nikon LS2000 and batch slide adaptor but as I currently do not have a SCSI-capable PC that has been retired (at least temporarily).
I have scanned all my 35mm negs on a flatbed scanner - Canon 9950f. The LS2000 seemed to reject most of the film due to a (slight) curl plus the ability to scan multiple strips at once (5 strips of up to 6, but all of mine are cut into 4 so 5x4 = 20 frames at once). My workflow is to scan the entire bed as a raw file in Vuescan (which creates a huge file) and then re-scan into individual RAW files for each frame. Given the speed of the scanner this is the most efficient scanning method I have found, and also results in less wear-and-tear on the scanner. The only downside is that as the Canon ages I have started to get streaks when I scan on the outer strips. I am unsure if the CCD needs cleaning or the scanning light source is failing due to age, but I now can only use 4 of the 5 strips in the holder reliably.
For 110 and 126 film I use custom holders which are available online to hold the film to scan flat on the Canon 9950f. They are not great but I don't have a lot of film in this format. I bought an adaptor for the LS2000 to scan Advantix film but I never got it to work properly - nowadays they go for a fortune on eBay so I may have no choice but to break open the canister to scan that film. For 120 negs I have an adaptor on the Canon which allows me to scan 2 strips at once. I only scan those at 1200dpi, which is good enough for my purposes.
I save everything as RAW - storage is cheap and I never want to go through this again. I only scan at 2400 dpi (although I have done the 110 negs at 4800dpi). Quite simply, these negatives are family photos taken on a cheap camera, and the sharpness isn't there to justify any more. Having said that, I have done side-by-side comparison between a scan of the negative @ 2400dpi and a 6x4 photo of the same frame and the negative definitely has more shadow & highlight detail but only slightly more sharpness. When I have compared the 110 negs with the scans of 6x4 prints I would rate them neck-and-neck for sharpness. I have considered trying to photograph the 110 neg with a DSLR to see if there is any more sharpness but in all honesty I doubt it exists in there.
With regards to your 'quick and dirty' option for previews/proofs, for a slightly cheaper cost than the low-grade negative scanners, there is an adaptor designed to use a smartphone. It will do a simple color inversion and rough removal of the orange base - not good enough for anything other than identifying the subject but that seems to be all you want to do.
There doesn't seem to have been much improvement in film scanning technology or quality in recent years - as everyone has moved to digital it seems to be all but forgotten. The market for devices seems to have split to either the ultra-high-end or cheap rubbish, with few options for batch scanning still available. Hence the reason my primary scanning equipment is 15 year s old. I just hope it doesn't die before I get everything done! I have managed to make good use of the recent lock-in period and get through another 100 rolls of 35mm, but there is still plenty of rolls to go!