1) Don't see the point of reflowing old cards. More modern cards run much MUCH hotter, the extreme temperature changes from hot to cold casues cracks in the solder, when relowing a card your hoping to melt the solder somewhat to fill in these cracks. Old cards simply don't get hot enough for this to be a problem.

2) Yes it just works (or not) you wont hurt anything if it's not right.

3) Up to you, If the card is doing everything you want is it worth the risk on older hardware, Sometimes I do, sometimes I don't. Initially up to you though.

4) If you don't want the TV part you can use the generic drivers, note the TV card isn't using standard DVI however it seems you just need a "P&D adapter" which are still fairly common.
Voodoo3 3500TV, connect to monitor?

5) pass

6) I don't think Voodoo 4/5 are bad, its more that Glide was pretty much finished around the era of the V3 so no games really required anything more powerful. Made more sense to go out and buy a cheaper and better performing D3D card from Nvidia, so were rare even back then.
Nowadays they are sort after as that extra power can be used for things like enabling AA but are priced out of most peoples budgets.
Compatibility is also an issue with some games been locked to a V1 or maybe V2 at best.

Think that with the current pricing of v5, you can get other cards, that will do the same, just faster 😜, if you are into "newer" games. I do like mine.

They are the fastest voodoos you can get, maybe some compatibility issues for older stuff (dont know, cus I havent played anything older than 97).
I dont have a crt, nor do I want one, I also dont wanna play at 800x600, so v5 is as low as want to go with my usecase, and even that is sometimes meh... There are fanatics(dumbasses) on both sides, 3dfx and anti-3dfx, so you know, form your own opinion 😀 its not like the debate is not for a 20y old hardware, so very important stuff in life!

More like curiosity. 😁 Thanks for answers, I noticed 20MHz does a big difference on these old goodies and nowadays 1GHz is nothing. 🤣

Regarding 1, I fixed around 20-30 V2 cards. Most of them had bad solder joints on the FBI/TMUs. For some reason the solder on these cards (regardless of the brand) has turned to mush. The failures I'm describeing are not due to mechanical damage.

Well its been good 20 years since the cards were made. And I guess you could actually use v2 for a couple of years when it was current, so you know, dont think we will be seeing rtx3090 cards after 20y 😁

Yes, nowadays, and I think that's good, no matter which card, no matter if too fast, as for DOS and early 3D gaming all parts matter or game will be too fast.

But again, what's the deal with V3 cards? I heard Velocity is too slow, and 2000, 3000 and 3500 are good to go but their clock speed is different and as owner (already) of 2000 and 3000 I see the difference and it's only 20MHz. 😁

Well you have to look at the % difference, cus thats the change in fps more or less. Does it matter to you? Up to you to decide.