@Lex_Luthor
First, welcome back!
There are a number of threads both here and on other forums that talk about Sampires and the skills, stats, and suit you'll need.
I am far from the most knowledgeable or skilled Sampire player, but may be able to get you started with this.
For your 1., I would drop the 5 off Intel and put it into Dex. More Dex = more stamina, faster swings, more leeching back life (and mana if you have mana leech weapons). I believe the swing speed tic for stamina is at 120, so if you take any damage you'll drop below 120 and drop swing speed. This is all dependent on your weapon speed and any Swing Speed Increase gear, Stamina Increase gear, etc.
For your 2., you need high SSI to keep swinging more powerful, slow weapons at max swing rate. That's kind of the bread and butter of the Sampire. You can't leech if you're not hitting. So, lot's of SSI and stamina gear. You also need high Hit Chance Increase to make sure those swings connect, high defense to avoid being hit, and max resists for when you do get hit. Also as much strength as possible to up your damage (and therefore the amount you leech back). You're mana needs will probably come from 10 intel and gear, but you can adjust as you see fit.
Sampires are powerful in PvM but need a lot of gear for high end play. It may take awhile to get it all. You do not need 100m gold per piece gear to be highly effective for many (or most) mobs. That high end build/gear is really for solo'ing bosses or champs, 2 things that were not around 20 years ago!
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For your paladin, yes a basic paladin is still highly effective and can compete with Sampires all the way up to mid level bosses (maybe high end bosses?). However, getting the right gear can be even more cost/time intensive.
Skills go to 120 now, so drop one of the seven and take the other six up to 120. (Or, get a soul stone and stone it off so you don't loose the skill).
120 Weapon
120 Tac
120 Parry
120 Chiv
120 Anat
120 Resist
This is the build I run. You need hit life leech weapons. It is more difficult than a Sampire (to me) because of the different ways leech is calculated between Vampiric Embrace and Hit Life Leech. However, you get all the benefits of having a shield (and it's mods) and you don't have to worry about getting an additional 25% fire resist. You also don't have to worry about corrupted life aura as you can just switch out a weapon and still heal with Chiv.
They're are significant trade off's to either build. Find the one you enjoy, and good luck!