(1)

Among the given molecules/ion, ${\mathrm{BF}}_3$ acts as a Lewis acid as it is an electron deficient species, it can accept a lone pair of electrons.
 

(4)

$\begin{array}{cc} \mathrm{Bronsted} \mathrm{acid} & \mathrm{Conjugate} \mathrm{base}\\ {\mathrm{H}}_2\mathrm{O}& {\mathrm{OH}}^{-}\\ \mathrm{HF}& {\mathrm{F}}^{-}\end{array}$

(3)

HCl cannot accept ${\mathrm{H}}^{+}$ ion, therefore cannot act as Bronsted Base.
 

(2)

${\mathrm{BF}}_3$ $\to$ Lewis acid (incomplete octet)

${\mathrm{PF}}_3$ $\to$ Lewis base (presence of lone pair on P atom)

${\mathrm{CF}}_4$ $\to$ Complete octet

${\mathrm{SiF}}_4$$\to$ Lewis acid (empty d-orbital in Si-atom)