The game will automatically assign new skills to any empty slots in your hotkey menu. However, if you click on any of the skill slots in the bottom right, you can assign/unassign whichever attack/skill you want.
Critical chance can not be less than 5% nor more than 95%.
The base chance for bows is 5%.
Passives
There is a full list of general critical strike passives on the wiki.
- 3 x Increased Critical Strike Chance (20%)
- 15 x Increased Critical Strike Chance (15%)
- 1 x Assassination (30% Increased Critical Strike Chance, 35% Increased Critical Strike Multiplier)
- 2 x Bloodthirst (45% Increased Critical Strike Chance)
- 1 x Mental Acuity (30% Increased Critical Strike Chance, 20 Intelligence)
This gives a combined total of +400%
There is another list of Bow specific passives giving a further +120%
Items
Out of the different mods, the "of Incision" suffix gives the most at +38%. This can't appear on all items. however if it could then it would give 304% (only counting 8 times because of the gloves below).
The unique gloves Maligaro's Virtuosity can be used with a bow and gives +50%
Gems
There is the support gem Increased Critical Strikes which gives about +105% at level 20.
Skills
Some skills give a critical strike chance bonus. For example Elemental Hit gives a +4% for every quality%. (so +80% at max quality)
Curse
There is the curse Critical Weakness which gives +10%. However this is treated differently and added after everything else.
Final Calculation
Total Possible Crit Chance with a bow is 5% * (100% + 400% + 120% + (8*38%) + 50% + 105% + 80%) + 10% = ~73%
Or an increase of just short of 1,500%. Not that this is practical, but it covers the different ways to boost crit chance.
edit: Assassination has 30cc 35cd, my current version: 1.2 (I didn't check values of other Nodes)
Best Answer
Bleeds can only be applied by attacks dealing physical damage, this is why the passive node says "Attacks have 15% chance to cause bleeding". This does include projectile attacks like those from bows. You can also link bow skills like puncture to a trap support gem. So yes, depending on the set up you can cause bleeds with projectiles (from attacks) and traps.
Poison can be caused by any damaging hit (attack or spell, doesn't matter for poison) that deals physical and/or chaos damage, assuming you have some % chance to poison on hit affecting whatever skill you are trying to poison with.